The genus Entoloma (Basidiomycota, Agaricales) in Europe: new taxa and amended species concepts in a phylogenetic context; neo-, lecto- and epitypifications of classical names

Abstract

The taxonomy and phylogeny of several clades of the genus Entoloma were revised using morphological and molecular genetic methods. Phylogenetic relationships among European species of the clades /Alboleptonia, /Caeruleopolitum, /Claudopus, /Griseorubidum, /Leptonia, /Olivaceotinctum, /Omphaliopsis, /Pouzarella, /Prunuloides, /Sphagneti, /Turfosa, /Undulatosporum, /Velenovskyi, and /Vinaceum were inferred using 694 newly generated sequences derived from the nrDNA ITS region including 80 sequences from type specimens. Anticipating the second volume of a completely revised monograph of the genus Entoloma in Europe, the following names are neotypified or epitypes are designated where, in case holotypes or lectotypes appeared unsuitable for molecular studies, viz. E. araneosum, E. byssisedum, E. griseorubidum, E. hirtum, E. lanicum, E. neglectum, E. ollare, E. opacum, E. plebejum, E. resutum, E. rusticoides, E. sericellum, E. triste, E. undatum, E. velenovskyi, and E. versatile. New type sequences for E. alliodorum, E. asperum, E. brunneoflocculosum, E. caeruleopolitum, E. calaminare, E. canosericeum, E. cettoi, E. cuboidoalbum, E. indutoides, E. iodiolens, E. jahnii, E. milleri, E. moguntinum, E. olivaceotinctum, E. ostreatum, E. politoflavipes, E. polyangulatum, E. pseudoconferendum, E. pseudonigellum, E. pseudosericeoides, E. ritae, E. sericeoides, E. sordidolamellatum, and E. undulatosporum have been generated and deposited in GenBank. Twenty-nine species new to science are described and illustrated, viz. E. albostriatum, E. amabile, E. assimile, E. bresadolae, E. brunneostrigosum, E. chloridicolor, E. cassiopeia, E. chioneum, E. cognatum, E. cornatum, E. eborinum, E. ermineum, E. fraudans, E. fusconigrum, E. griseopulchrum, E. hirsutum, E. ludwigii, E. nanoalbum, E. nix, E. olivaceovirens, E. ostreatum, E. paraindutoides, E. peraraneosum, E. pilosum, E. pumilionis, E. skadiae, E. umbrinotinctum, E. vilae, and E. weiriorum, and Entoloma sect. Atricoloria is described as new to science. The name E. myochroum is validated and the replacement name E. cobaltichlorum is proposed. Morphological and molecular studies made it necessary to provide new, amended descriptions for E. alliodorum, E. anthracinum, E. araneosum, E. brunneoflocculosum, E. byssisedum, E. calaminare, E. canosericeum, E. dysthaloides, E. griseorubidum, E. flocculosum, E. indutoides, E. inopiliforme, E. hirtum, E. lanicum, E. lidbergii, E. milleri, E. myochroum, E. neglectum, E. olivaceotinctum, E. ollare, E. opacum, E. plebejum, E. polyangulatum, E. pseudonigellum, E. pseudoparasiticum, E. pseudosericeoides, E. pseudoturbidum, E. resutum, E. rusticoides, E. sericellum, E. sericeoides, E. sordidolamellatum, E. triste, E. undatum, E. undulatosporum, E. velenovskyi, and E. versatile.

Citation: Noordeloos ME, Reschke K, Morozova O, Jordal JB, Jansen GM, Brandrud TE, Bendiksen E, Larsson E, Karich A, Krisai-Greilhuber I, Ainsworth AM, Nuytinck J, Borovička J, van der Vegte MJC, Frøslev TG, Dima B (2026). The genus Entoloma (Basidiomycota, Agaricales) in Europe: new taxa and amended species concepts in a phylogenetic context; neo-, lecto- and epitypifications of classical names. Persoonia 56: 200–307. doi: 10.3114/persoonia.2026.56.03

INTRODUCTION

This study is part of a large-scale molecular phylogenetic and morphological revision of the genus Entoloma in Europe, working towards a new, completely revised monograph of all European species in two volumes of Fungi Europaei 5. The first part was published in Noordeloos et al. (2022a), the second and final volume is planned to be finished in 2026. The material in the present study comes from various sources. In the Nordic countries, much work has been done on Entoloma in the framework of the Norwegian Entoloma project and studies of the subarctic Mycota in Sweden resulting in a constant flow of publications in recent years (Brandrud et al. 2018, 2019, Noordeloos et al. 2018, 2021, Haelewaters et al. 2020, Crous et al. 2021), and many collections have been studied from Central, Southern and Eastern Europe, including the European part of Russia. An attempt has been made to transform the traditional morphological approach as used in earlier monographs (Noordeloos 1992, 2004) into a more integrated species concept, including morphology, ecology, and molecular data. The present contribution deals with a series of clades within the well-supported and large /Cyanula–Inocephalus superclade of the multi-locus phylogenies presented by Co-David et al. (2009) and Baroni & Matheny (2011), viz. the /Alboleptonia, /Leptonia, /Undulatosporum, /Griseorubidum, /Olivaceotinctum, /Claudopus and /Velenovskyi clades, as well as the /Pouzarella, the so-called basal grade (including the /Caeruleopolitum, /Prunuloides, /Sphagneti, /Turfosa and /Vinaceum clades), and some lineages of uncertain affinities.

MATERIAL AND METHODS

Morphology

All studied collections were photographed in the field and attention was paid in observing the surrounding vegetation and putative ecology for each collection based on above-ground observations. The material was described after collecting to document the ephemeral macroscopic characters (especially colours) and dried and stored in the respective fungaria. Microscopic characters were studied with standard light microscopy methods. Basidiospores, basidia, cystidia, and tramal structures were observed in squash preparations of small parts of the lamellae in water (fresh specimens) or in 5 % KOH or 1 % Congo Red in concentrated NH₄OH (fungarium specimens). The pileipellis was examined on a radial section of the pileus in water (fresh specimens) or in a weak NH₄OH solution. For basidiospores, measurements are given as follows: minimum length–maximum length × minimum width–maximum width of at least 95 % of the spores. In some cases, extreme values are given in brackets. Average spore size refers to the range of the average values of single collections. The factors Q (quotient of length and width) and Qav (mean of Qvalues) were calculated. The range Q = 1.10–1.50, Qav = 1.20–1.30 means Q value of all measured spores ranges from 1.10 to 1.50, Qav. = the range of mean Q values for all collections. Normally 10–15 basidiospores have been measured per specimen, and usually 1–2 specimens per collection were microscopically studied. The number of microscopically studied specimens is given in brackets: (80/4) means 80 spores measured from 4 specimens. Cystidia and basidia dimensions are based on observing at least 10 structures per collection. Basidia were measured without the sterigmata. Pileipellis structures were observed on radial sections. All studied material is deposited in the fungaria of Oslo (O), Gothenburg (GB), Leiden (L), or St Petersburg (LE), unless otherwise indicated. For details on the characters used in the taxonomy of Entoloma the reader is referred to Noordeloos et al. (2022a).

DNA extraction and sequencing

Fungal DNA was extracted and the nrDNA ITS barcode region sequenced as described in Dima et al. (2016), Morozova et al. (2018), Papp & Dima (2018), Hahn et al. (2019) and Reschke et al. (2022a). At Naturalis Biodiversity Center, Illumina MiSeq sequencing was used for herbarium specimens. The ITS1 and ITS2 regions were amplified separately using primer combinations ITS1-F/ITS2 and ITS3/ITS4 with Nextera™ tails (Illumina). Library preparation, sequencing and processing of Illumina sequence reads were performed as described in Delgat et al. (2019). Sequencing of some material was performed in the Norwegian Barcode of Life (NorBOL) project or by Alvalab (Oviedo, Spain). Chromatograms were checked and edited with the CodonCode Aligner v. 9.0.2 package (CodonCode Corp., Centerville, Massachusetts, USA) or Geneious v. 2019.2.1 (Biomatters Ltd., Auckland, New Zealand). Sequence comparisons with public and our own databases followed Noordeloos et al. (2017). Additional sequences were downloaded from GenBank (https://www.ncbi.nlm.nih.gov/) and UNITE (https://unite.ut.ee/) databases. The sequences were aligned in MAFFT v. 7.490 (Katoh & Standley 2013) using the E-INS-i algorithm. The resulting alignments were examined and manually pruned in AliView v. 1.26 (Larsson 2014). Maximum likelihood trees were calculated in RAxML v. 8.2.12 (Stamatakis 2014) using the GTRCAT model with 25 per site rate categories, 1000 rapid bootstraps and a thorough ML search thereafter, both with the standard seed ‘12345’. The resulting phylograms were inspected in FigTree v. 1.4.4 (Rambaut 2014) and thereafter edited in MEGA v. 7 (Kumar et al. 2016) and Microsoft PowerPoint (Microsoft 365).

RESULTS

Phylogeny

A total of 694 new ITS sequences were generated for this study, including 80 sequences of type specimens. The newly obtained sequences, together with 406 ITS sequences downloaded from GenBank and UNITE databases, were used as the basis for our phylogenetic analyses (Suppl. Table 1). For each of the main clades discussed in this study, separate trees were made. For /Undulatosporum incl. /Olivaceotinctum, 117 new and 27 database sequences were used; for /Griseorubidum including /Cornatum, 13 new and 14 database sequences; for /Velenovskyi, 19 new and 21 database sequences; for /Claudopus, 157 new and 94 database sequences; for /Alboleptonia, 102 new and 38 database sequences; for /Leptonia, 21 new and 51 database sequences; for /Pouzarella, 100 new sequences and 68 database sequences; for /Rusticoides, 74 new and 44 database sequences; and for the basal grade, 91 new and 54 database sequences. A reduced set of those alignments together with 35 additional GenBank sequences were used for the overview tree (Fig. 1). The resulting phylogenetic trees show differences in resolution between certain clades: the best resolved trees were obtained for subg. Pouzarella and sect. Griseorubida, which include several well-supported backbone branches and a comparatively high proportion of well-supported subclades. On the contrary, the trees of subg. Omphaliopsis and subg. Claudopus do not contain supported backbone branches and contain comparatively few supported subclades. The clades treated at species level were in general well-supported. Most of the species have rather uniform ITS sequences with only low or even no variability in the sequences analysed for this study. However, some species have a comparatively high variability, including distinct differences in several nucleotides and ambiguous nucleotides at certain sites. The resulting clades of such species are sometimes poorly supported, e.g., the clades of E. sericellum and E. undatum. Other species clades, such as E. velenovskyi and E. ostreatum, have distinct subclades, which potentially could represent different species. The backbone of the overview tree has generally low support values. However, the structure agrees with previous multi-gene studies where comparable relations are found, e.g. subg. Cyanula neighbouring subg. Inocephalus (Karstedt & Kapelari 2013), the positions of the basal grade and subg. Entoloma (Morgado et al. 2013), and the relation of the subgenera Claudopus, Leptonia and Nolanea (Reschke et al. 2022a).

Fig. 1.

Maximum Likelihood (RAxML) overview phylogenetic tree based on nrDNA ITS sequences of the genus Entoloma focusing on the studied lineages. ML bootstrap support values (> 50 %) are shown at the branches regardless of any value. Blue clades are treated in this paper. The scale bar indicates expected changes per site per branch.

Taxonomic part

Order of the clades/sections/subgenera treated here follow the topology of the phylogenetic tree in Fig. 1, while the species within each clade are presented in alphabetical order.

/Undulatosporum clade – Entoloma sect. Erophila

Entoloma sect. Erophila (Romagn.) Noordel., Persoonia 11: 86. 1980. amend. MB 860554.

Basionym: Rhodophyllus sect. Erophili Romagn., Bull. Mens. Soc. linn. Lyon 43: 332. 1974. MB 634423.

Synonym: Entoloma sect. Tristia (Noordel.) Noordel. & Wölfel., Österr. Z. Pilzk. 6: 26. 1997. MB 846106.

Type species: Entoloma erophilum (Fr.) P. Karst = Entoloma plebejum (Kalchbr.) Noordel.

Description (amended here): Basidiomata collybioid, tricholomatoid, mycenoid or omphalinoid. Pileus conical-convex or convex-umbilicate, sometimes deeply umbilicate; hygrophanous, or only weakly so, usually not translucently striate, often radially fibrous-micaceous to slightly to distinctly squamulose. Lamellae often tinged grey; stipe central. Basidiospores heterodiametrical to subisodiametrical with a 7–10 angular to subnodulose outline. Lamella edge fertile or heterogeneous with pronounced protruding cheilocystidia. Pileipellis usually consists of a transition between a cutis and trichoderm of cylindrical hyphae with clavate or subclavate terminal elements with intracellular pigment. Clamp-connections usually present.

Notes: In Europe the /Undulatosporum clade comprises about 30 species with a collybioid, tricholomatoid, mycenoid or omphalinoid habit. The species in this group usually have a depressed to umbilicate pileus with a differentiated pileipellis, usually of a transition between a cutis and trichoderm of cylindrical hyphae with clavate or subclavate terminal elements with intracellular pigment, and clamped hyphae. Many species have irregular angular spores with a nodulose–angular outline, hence the name of this clade. Most of the species have relatively dark brown to almost black colours, and the majority occur in rather exposed habitats, such as subarctic or subalpine heaths and snowbed communities, pioneer vegetation such as coastal dunes and sandflats, as well as xerophytic grasslands on calcareous soils. Several of these taxa are exclusively vernal or appear in the colder months of the year. In the traditional morphology-based classifications, species belonging to this clade were placed in different subgenera: E. undulatosporum and E. triste in subgenus Nolanea, sect. Tristia (Noordeloos 1987, Wölfel & Noordeloos 1997a), and E. opacum, E. plebeioides, E. plebejum, and E. resutum in subgenus Inocephalus, sect. Erophila (Noordeloos 2004). Our phylogenetic studies, however, show that these species cluster together in a well-supported clade, together with several undescribed species (Fig. 2). Some of these species are described here as new, other phylogenetic species have insufficient data to be published formally now and have to remain unnamed for the time being. We propose to accommodate the species of this clade in the amended concept of sect. Erophila.

Fig. 2.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma sect. Erophila (= /Undulatosporum). ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma amabile J.B. Jordal, E. Larss., Noordel., O.V. Morozova & Dima, sp. nov. MB 860384. Fig. 3.

Fig. 3.

Entoloma amabile (A–D. GB-0207746, holotype; E. L0607184). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E. Pileipellis. Photos: A by J.-M. Trendel; B by J.B. Jordal; C by G.M. Jansen. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores, cheilocystidia), 40 μm (pileipellis).

Etymology: amabilis (Lat.) – lovely, referring to the lovely appearance of this species.

Typus: Sweden, Pite lappmark, Arjeplog, Skarrim, 10 Aug. 2018, J.B. Jordal, E. Larsson & J. Vauras, EL6-18 (holotype GB-0207746); ITS sequence, GenBank PV018335.

Description: Basidiomata collybioid. Pileus 10–20 mm wide, conico-convex then convex with minute umbo, with straight margin, pale brown, almost white at margin, deeply translucently striate, probably hygrophanous, medium brown at centre, initially radially fibrillose, glabrescent with age, finally appearing rather smooth. Lamellae moderately distant (L = 24–28, l = 3), narrowly adnate, subventricose, white then pink with an entire, concolourous edge. Stipe 30–40 × 2–3 mm, cylindrical, white, fibrillose-striate. Context fragile, concolourous with surface. Smell indistinct, taste not noted. Basidiospores (50/3) 8.5–11.0 × 5.5–7.5 μm, on average 8.9–9.7 × 6.5–6.8 μm, Q = 1.30–1.70, Qav = 1.45–1.50; nodulose-angular, thin-walled, heterodiametrical. Basidia 22–29 × 9–14 μm, clavate, 4-spored, clamped. Lamella edge heterogeneous, with scattered, subcylindrical to narrowly clavate cheilocystidia, 30–44 × 8–12 μm. Pileipellis a cutis made up of cylindrical hyphae 4–9 μm wide, with brown granular and diffuse intracellular pigment. Stipitipellis a cutis of cylindrical hyphae, 5–14 μm wide; caulocystidia absent. Clamp-connections present in hymenium, rare in other tissues.

Habitat and distribution: The holotype collection originated from a rich alpine meadow, bordering a riverlet with Bistorta vivipara, Thalictrum alpinum and Salix hastata. This species has also been found on lakeside soil with Salix in subarctic Russia, and in a mixed broad-leaved alluvial forest (France). Known from Northern Sweden, Northern Russia, and France.

Additional material examined: France, Alsace, Haguenau, Schirrheinerweg Biological Reserve, Haguenau forest, plot 26, 1 Sep. 2023, J.-M. Trendel, JMT-23090113 (L0607184). Russia, Murmansk Oblast, vicinities of Apatity, bank of the Imandra Lake, on soil on roadside under Salix sp., 21 Aug. 2023, O. Morozova, 2AP23 (LE F-344066).

Notes: Entoloma amabile is distinguished by the pale, hardly fibrillose pileus, white, strongly fibrillose stipe, and presence of scattered cheilocystidia. Entoloma milleri from Svalbard is much darker, has different spores and a distant phylogenetic relationship within the sect. Erophila.

Entoloma anthracinum (J. Favre) Noordel., Persoonia 11(2): 228. 1981. MB 112291. Fig. 4.

Fig. 4.

Entoloma anthracinum (A, I. Voto fu14, holotype of E. phaeocarpoides; B. FP-2024-01-06-1; C–F. Favre (1960); G, H. BG-2019-11-23). A, B, G, H. Habit in situ. C. Lectotype of E. anthracinum. D. Lectotype of E. atropellitum. E. Line drawings of lectotype of E. anthracinum. F. Line drawings of lectotype of E. atropellitum. I. Basidiospores. Photos: A, I by P. Voto; B by P. Finy; G, H by G. Benkő. Scale bars: 1 cm (habit), 10 μm (spores).

Basionym: Rhodophyllus anthracinus J. Favre, Ergebn. wiss. Unters. Schweiz. NatnParks 5(no. 33): 200. 1955. MB 305208.

Synonyms: Entoloma subcollariatum (Kühner) Bon, Bull. trimest Féd. Mycol. Dauphiné-Savoie 31(no. 122): 26. 1991. MB 128983

Entoloma phaeocarpoides Voto, Mycological Observations 4: 33. 2022. MB 844177

Rhodophyllus atropellitus J. Favre, Ergebn. wiss. Unters. schweiz. NatnParks 5(no. 33): 200. 1955. MB 305212 (see notes, below).

Misapplied names: Rhodophyllus anthracinus sensu Kühner, Bull Soc. Mycol. France 93: 472–480 (1977), and Entoloma anthracinum sensu Noordeloos, Persoonia 12: 289–290 (1984).

Typus: Switzerland, Graubünden, Val Nüglia, Region of Fuorn, National Park, on bare ground, with Saxifraga oppositifolia, Ranunculus alpestris, Festuca pumila, 31 Aug. 1949, J. Favre, GK 13906 (lectotype designated in Kokkonen 2015, deposited at G); ITS sequence, GenBank LN850598.

Description (amended here): Basidiomata collybioid to omphalinoid. Pileus 20–30 mm wide, convex, with weak umbo or slightly depressed at centre with thin, incurved margin, slightly hygrophanous, not translucently striate, blackish brown to umber brown when moist, with slightly paler margin, pallescent to grey brown when dry, with radially fibrillose-micaceous, at centre often somewhat granular surface. Lamellae moderately crowded (L = 20–25, l = 1–3–7), relatively broad, up to 4.5 mm, adnate-emarginate or adnate with short decurrent tooth, rather dark grey brown with pink tinge, often slightly veined on sides. Stipe 20–40 × 3–5 mm, usually attenuated towards base, but sometimes equal, solid then hollow, concolourous or distinctly paler than pileus, glabrous or slightly fibrillose. Context grey. Smell and taste indistinct. Basidiospores (150/10) 7.5–12.0 × 5.5–10.0 μm, on average 8.5–10.3 × 6.5–7.5 μm, Q = (1.10–)1.20–1.50, Qav = 1.30–1.35, heterodiametrical in outline with 5–8 nodulose angles in side view. Basidia 24–42 × 8.0–13.0 μm, 4- or 2-spored, clamped. Lamella edge fertile. Cystidia absent. Hymenophoral trama made up of long, cylindrical to fusiform elements, 120–200 × 5–14 mm. Pileipellis a differentiated cutis with narrow, cylindrical hyphae, 3–15 µm wide, with cylindrical to subclavate terminal elements, 10–20 μm wide; pigment brown, intracellular. Stipitipellis a cutis of narrow, cylindrical hyphae. Caulocystidia absent. Clamp-connections present in all tissues.

Habitat and distribution: Solitary or in small groups in rather exposed habitats with natural disturbances, in arctic and alpine zones in dwarf-shrub vegetation, as well in coastal sand dunes in association with Ammophila, also found in continental, steppe-like sites. Known from European Russia, Central Europe including the Alps, and from a few places along the Atlantic and Adriatic coast in West and southern Europe. The species has also been verified from Iran (ITS sequence, GenBank MH453494).

Additional material examined: Austria, Niederösterreich, Pottendorf: Landegg, Leitha-Au Südost, 4 Sep. 2008, M. Beisenherz (WU-Myc 28494); Niederösterreich, Lichtenwörth, Zillingsdorfer Wald Ost, G. Koller, Hausknecht 3403.0 (WU-Myc 24866); Wien, Donaustadt, Donauinsel, 19 Oct. 2007, T. Barta (WU-Myc 28003). France, Savoie, Vanoise National Park, Pralognan, at the foot of Col de Chavière, boundary of mineral soil, above the last Salix herbacea, alt. 2600 m, 12 Sep. 1969, R. Kühner, K 69–304 (G262078, holotype of Rhodophyllus subcollariatus). Germany, Hessen, Frankfurt am Main, Campus Riedberge, vor OSC, on soil in lawn, 25 Feb. 2018, K. Reschke, KaiR1473 (B 70 0105520); Hessen, Marburg-Biedenkopf, Amöneburg, wayside, on rather bare soil, 21 Jan, 2018, C. Manz & M. Theiss aCM10 (B 70 0105491). Hungary, Vas, Szombathely, in lawn in front of a shopping centre, 23 Nov. 2019, G. Benkő & K. Fábrics, BG-2019-11-23 (ELTE); Budapest, 18 Nov. 2022, Z. Bratek, BZ-2022-11-18 (ELTE); Bács-Kiskun, Fülöpháza, 6 Jan. 2024, P. Finy, FP-2024-01-06-1; Pest, Csévharaszt, 5 Mar. 2024, I. Ölvedi, ÖP-2024-03-05-1 (ELTE); ibid., 5 Mar. 2024, I. Ölvedi, ÖP-2024-03-05-2 (ELTE). Italy, Veneto, Rovigo, Rosolina, Rosolina Mare, Porto Caleri, associated with Pleurochaete squarrosa, 14 Jan. 2007, P. Voto, fu14 (VER, holotype of E. phaeocarpoides). Russia, Volgograd Oblast, near Chapurniki Village, “Chapurnikovskaya Balka” protected area, sandy steppe, 18 Oct. 2013, T. Svetasheva (LE F-316081); ibid., (LE F-316082); Astrakhan Oblast, Chernoyarsky District, on roadside soil, 22 Oct. 2019, Yu. Rebriev, BM1346 (LE F-316083). The Netherlands, prov. Noord-Holland, Amsterdamse Waterleiding Duinen, Van Limburg Stirum Vallei, in moist dune slack on bare, calcareous sand close to Ammophila arenaria, 14 Jan. 2018, L.M. Jalink, L4406372.

Notes: Entoloma anthracinum apparently is a widespread species with a preference for dynamic ecological conditions, such as high alpine snowbed communities and the sparsely vegetated, rather exposed coastal dune habitats in the Atlantic and Mediterranean regions, as well as dry, steppe vegetation and dunes in Central Europe. Kokkonen (2015) designated a lectotype and compared it with the lectotype of E. subcollariatum which is considered conspecific. Also, the recently described E. phaeocarpoides has an identical ITS barcode. Favre (1955) described and depicted rather regularly 5–7-angled spores with pronounced angles. However, Kokkonen (2015) indicated that the spores of the lectotypes of E. anthracinum, and E. subcollariatum (viz. 6–9, usually 6–8-angled) were deviating from their respective protologues, which place them in the /Undulatosporum clade, and not in subgenus Entoloma, as suggested by Kühner (1977) and Noordeloos (1984). This is confirmed by our examination of the additional collections of this species. The sizes of the spores vary also considerably, which may be due to a varying number of 2- and 4-spored basidia. Kühner (1977) in his impressive study of subgenus Entoloma (= Rhodopolia) in the Alps gives three different descriptions of what he considered to be E. anthracinum. In the discussion he makes an interesting remark, viz. “The spores of Rhodophyllus anthracinus in the herbarium of Favre seem to us different from those depicted by the author (i.e., R. Kühner), and from those of the collections we just described above as E. anthracinum. In fact, they show an outline that is not so much different from R. atropellitus J. Favre, being nodulose-angled with 8–9(–10) angles. They also have the same dimensions as our E. anthracinum”. This observation confirms those mentioned above of Kokkonen (2015), and supports our hypothesis, that the descriptions of E. anthracinum by Kühner (1977) and Noordeloos (1984) actually refer to another species, with spores being more or less regularly angular, and a pileipellis in form of a thin cutis or ixocutis of narrow, cylindrical, 3–7 µm wide hyphae, overlaying a subpellis of much wider hyphae, typical for species in subgen. Entoloma (/Rhodopolia). Kühner (1977) also studied the original material (lectotype) of E. atropellitum, and concluded it might be considered a dwarfish form of E. anthracinum. He also compared the spore shape with those of E. sphagneti, and wondered whether E. atropellitum might be a dwarfish alpine form of that species. As we know now, however, E. sphagneti is a quite distinct and different species with a very distant phylogenetic position (Morgado et al. 2013). In summary, we believe now that E. anthracinum in its original sense, including E. atropellitum, belongs to sect. Erophila, characterised by relatively small, very dark basidiomata and heterodiametrical, nodulose-angled spores. As shown above, it is not a strictly alpine species.

Entoloma cassiopeia Noordel., P.-A. Moreau, Reschke & Dima, sp. nov. MB 860386. Fig. 5A, B.

Fig. 5.

A, B. Entoloma cassiopeia (GB-0207742, holotype). A. Habit. B. Basidiospores. C–F. Entoloma griseopulchrum (L4343904, holotype). C. Habit in situ. D. Habit in studio. E. Basidiospores. F. Pileipellis. G, H. Entoloma milleri (O-F-74757, holotype). G. Habit. H. Basidiospores. Photos: A by P.-A. Moreau; C by M.J.C. van der Vegte; D–F by G.M. Jansen; G by G. Gulden. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores), 40 μm (pileipellis).

Etymology: Κασσιóπεια (Greek) – referring to the association with Cassiope species.

Typus: Sweden, Torne Lappmark, Jukkasjärvi, Abisko, Latnja, among mosses on an alpine cliff with Cassiope, 18 Aug. 2013, P.-A. Moreau, E. Larsson & J. Vauras, PAM13-40 (holotype GB-0207742); ITS sequence, GenBank PV018337.

Description: Basidiomata mycenoid. Pileus about 15–20 mm wide, conical then conico-convex, indistinctly hygrophanous, sepia brown with darker centre, translucently striate up to centre, innately radially fibrillose, centre slightly rugulose. Lamellae moderately distant (L = 25–30, l = 3–5), adnate-emarginate, ventricose, pale cream then brownish pink with irregular, concolourous edge. Stipe 40–50 × 2–3 mm, pale brown, like pileus margin or paler, with scattered silvery longitudinal fibrils. Context concolourous with surface. Smell and taste not distinctive. Basidiospores (20/1) 9.0–12.5 × 5.5–8.5 μm, on average 9.5–10.7 × 6.5– 7.2 µm, Q = 1.25–1.75, Qav = 1.45–1.50, nodulose-angular in side view with pronounced angles and sharp apiculus. Basidia 20–34 × 7–12 µm, 4-spored. Lamella edge heterogeneous. Cheilocystidia absent or sparse, subcylindrical, slightly protruding from hymenium, 40–50 × 5–11 µm wide. Pileipellis a transition from a cutis to a trichoderm, made up of 5–12 µm wide hyphae with inflated terminal elements, 6–22 µm wide; pigment intracellular, brown. Stipitipellis a cutis of cylindrical hyphae, 5–11 µm wide. Caulocystidia absent. Clamp-connections present in hymenium, elsewhere not found.

Habitat and distribution: Among mosses on an alpine cliff with Cassiope sp. Only known from one locality in Northern Sweden.

Notes: Entoloma cassiopeia belongs to a small, but well-supported subclade within sect. Erophila which represents one (or more) subarctic/alpine species, morphologically similar to, but phylogenetically distant from the above-described E. amabile from a similar habitat. We were, however, not able to establish consistent morphological differences between E. cassiopeia and E. amabile and they seem to have similar ecological requirements. However, the two are phylogenetically very distant, so they represent two well-separated barcode species. The subclade shows a considerable variation in ITS, so possibly more than one (barcode) species can be recognized within E. cassiopeia when more data are available.

Entoloma griseopulchrum M.v.d. Vegte, G.M. Jansen, Noordel. & Dima, sp. nov. MB 860383. Fig. 5C–F.

Etymology: griseus (Lat.) – grey; pulcher (Lat.) – beautiful.

Typus: The Netherlands, prov. Gelderland, Rheden, Heiderust, 26 Oct. 2022, M.J.C. van der Vegte & G.M. Jansen (holotype L4343904); ITS sequence, GenBank PX412037.

Description: Basidiomata mycenoid to collybioid. Pileus 10–20 mm wide, convex to plano convex usually with small umbo or slightly depressed centre, and involute then straight margin, pale grey to grey or dark brown grey sometimes almost black, but sometimes distinctly pale grey brown, indistinctly to distinctly hygrophanous, slightly to distinctly translucently striate when moist or not, slightly paler when dry, radially fibrillose to woolly-fibrillose, with silvery sheen (micaceous) and sometimes splitting when exposed, then showing the context of the pileus, resembling an Inocybe. Lamellae moderately distant (L = 14–20, I = 3), narrowly adnate, subventricose, up to 3.5 mm broad, pale to rather dark brown grey or olivaceous grey with pink tinge, with entire or eroded, concolourous or slightly paler edge, occasionally veined on the sides. Stipe 25–35 × 1–4 mm, cylindrical, narrowly hollow, at apex pale grey to pale greyish yellow, downwards grey brown or olivaceous grey, subpolished with scattered longitudinal fibrils, with white basal tomentum. Context very thin, pale brown. Smell faint or farinaceous; taste indistinct. Basidiospores (100/7) 7.5–11.5 × 5.0–7.0 μm, on average 8.5–9.7 × 6.0–6.2 μm, Q = 1.30–1.80, Qav = 1.45–1.6, many-angled, sometimes almost nodulose. Basidia 20–40 × 5–11 μm, 4-spored, clamped. Lamella edge fertile, no cystidia present. Hymenophoral trama made up of cylindrical hyphae, 4.5–15 μm wide, somewhat constricted at septa, hyaline. Pileipellis a cutis with transitions to a trichoderm, made up of cylindrical to slightly inflated hyphae, 7–22 μm wide, with brown, intracellular pigment. Stipitipellis a loose cutis of narrow, cylindrical hyphae, caulocystidia absent, Clamp-connections present, but scarce, often difficult to find.

Habitat and distribution: Terrestrial, among mosses in roadsides and in mixed forest on humus rich soil, with Quercus, Acer, sometimes also Picea and Abies. So far known from Denmark, Germany, and The Netherlands.

Additional material examined: Denmark, Jylland, Hjørring Kommunes Klitplantage, Rubjerg Knude, in Abies plantation on calcareous soil, 26 Jul. 2017, T. Læssøe, DMS-9199297 (C). Germany, Bayern, Landkreis Miesbach, Gemeinde Warngau, Taubenberg, Sulzgraben, in mixed mountain forest with Abies, Picea and Fagus on mineral rich soil, 27 Aug. 2020, M. Dondl, MD2020-02 (L0607590, as E. winterhoffii).

The Netherlands, prov. Drenthe, Mensingebos, along the road from Roden to Lieverden, 8 Sep. 1988, P.J. Keizer, 88318 (L4406371, as E. undulatosporum); ibid., 29 Jun. 1987, P.J. Keizer, 87011 (L4406370, as E. undulatosporum); ibid., 8 Sep. 1988, P.J. Keizer, (L4406373, as E. undulatosporum); prov. Zeeland, Axel, Axelse bos, 10 Aug. 1982, A. de Meyer, 349b (L4406374); prov. Gelderland, Heiderust, Rheden, 17 Oct. 2021. M.J.C. van der Vegte (L4343850); prov. Zuid-Holland, Voorschoten, Ter Horst, 28 Sep. 1977, M.E. Noordeloos s.n. (L4402044, as E. plebeioides).

Notes: Entoloma griseopulchrum differs from E. undulatosporum by the often umbonate, not umbilicate pileus and fibrillose stipe surface. Entoloma triste is macroscopically similar but has larger spores and more abundant clamp-connections. A collection made by M. Dondl (as E. winterhoffii) deviates a little in being pale grey, not as dark as the other collections, but otherwise it is very similar. The very rarely recorded E. winterhoffii differs by larger spores (Noordeloos 2004), but no ITS sequence is available of the holotype for comparison.

Entoloma milleri Noordel., Mem. New York Bot. Gard. 89: 103. 2004. MB 367425. Figs 5G, H.

Etymology: Named in honour of the North American mycologist, Orson K. Miller (1930–2006).

Typus: Norway, Svalbard, Oscar II land, Stuphallet, (± 500 m), on soil in Salix polaris vegetation among Racomitrium, 6 Aug. 1986, G. Gulden & K.M. Jensen, GG 226/86 (holotype, O-F-74757).

Description: Pileus 10–25 mm broad, campanulate to conico-convex, expanding with age, with small umbo and inflexed margin, not hygrophanous or translucently striate, dark grey brown, squamulose at centre (umbo), radially fibrillose elsewhere, becoming fissurate with age. Lamellae moderately crowded (L = 20–28, l = 1–3), deeply emarginate or adnate, subventricose, to 2.5 mm broad, pale grey to brown grey, with concolourous, entire edge. Stipe 10–30 × 1.5–3 mm, cylindrical, concolourous with pileus, innately fibrillose, white tomentose at base, solid. Context dark grey to grey brown. Smell and taste indistinct. Basidiospores (15/1) 9.0–12.0(–13.0) × 6.5–8.0(–9.0) μm, on average 10–11 × 7–7.5 μm, Q = 1.20–1.50, Qav = 1.40, heterodiametrical, many-angled almost nodulose in outline, rather thin walled. Basidia 20–50 × 10–18 μm, 4-spored, clamped. Lamella edge fertile. Cystidia absent. Hymenophoral trama regular, consisting of long, inflated elements, ca. 300 × 15–35 μm. Pileipellis a cutis to 15 μm wide, inflated hyphae, at centre forming a transition to a trichoderm of inflated terminal elements. Pileitrama regular, consisting of long, inflated elements, 50–200 × 10–30 μm. Pigment brown, intracellular, often as dark clots in plasma, in pileipellis and upper pileitrama. Stipitipellis a loose cutis of narrow cylindrical hyphae. Caulocystidia absent. Clamp-connections present in hymenium and trama of pileus, lacking very scarce in other tissues.

Habitat and distribution: Terrestrial in polar Dryas/Salix heath, among Racomitrium. Only known from Svalbard (Norway).

Notes: Entoloma milleri is distinctive on account of the grey colours, particularly of the lamellae, the squamulose pileus, and the relatively large, many-angled to nodulose, thin-walled spores. Entoloma resutum is somewhat similar, but has thicker-walled, regularly 6–7-angled spores, and has not been found in arctic(-alpine) environments. Entoloma hispidulum has similar spores and a squamulose pileus, but it has slenderer basidiomata with minutely encrusted hyphae in the pileipellis, is not arctic and belongs to the distant subgen. Leptonia.

Entoloma opacum Noordel., Beih. Nova Hedwigia 91: 135. 1987. MB 133098. Fig. 6.

Fig. 6.

Entoloma opacum (A, B, E. PRM 954078, epitype; C. MR-2024-03-04; D, F. L0607237). A–D. Habit. E. Basidiospores. F. Pileipellis. Photos: A, B, F by K. Tejkal; C by Re. Molnár; D, F by A. Grobelny. Scale bars: 1 cm (habit), 10 μm (spores), 20 μm (pileipellis).

Replaced synonym: Clitocybe opaca Velen., České Houby 2: 268. 1920. MB 272953, nom. illegit., Madrid, Art. 53.1, non Clitocybe opaca Gillet, Hyménomycètes (Alençon): 164. 1874. MB 184587.

Typus: Czechia, Central Bohemia, Mnichovice, Aug. 1918, J. Velenovský, 186 (holotype, PRC, as Clitocybe opaca Velen., non C. opaca (With.) Gillet). Czechia, Praha, 12 Mar. 2020, K. Tejkal (epitype PRM 954078, designated here, deposited at PRM, MBT 10028194, isoepitype in L); ITS sequence, GenBank PX412053.

Description (amended here): Basidiomata tricholomatoid, rather sturdy, with relatively short stipes. Pileus 20–50 mm wide, convex to plano-convex, with a flattened to slightly depressed centre, sometimes with a small papilla, with deflexed sometimes undulating margin, not hygrophanous or translucently striate, very dark, almost black at centre, dark grey to dark grey brown towards margin, often more or less variegated-marbled or with darker spots, sometimes paler, more silvery grey, when old sometimes turning to grey beige with darker centre, finely radially wrinkled or fibrillose-subtomentose, when exposed sometimes breaking up in irregular patches showing the paler trama of the pileus, never really squamulose. Lamellae moderately crowded (L = 40–60, l = 1–5), adnate, deeply emarginate, sometimes with decurrent tooth, arcuate to ventricose, whitish greyish, then sordid grey pink, entire or eroded, concolourous edge. Stipe 30–35 × 3–8 mm, usually shorter than diameter of pileus, cylindrical or tapering towards base, light brown to cream, much paler than pileus, at apex finely pruinose–flocculose, downwards silvery fibrillose, solid then hollow. Context thin to thick, concolourous or distinctly paler than surface. Smell and taste indistinct to slightly farinaceous. Basidiospores (100/7) 8.0–10.5 × 6.0–8.0 μm, on average 9.0–9.5 × 6.5–7.5 μm, Q = 1.25–1.40, Qav = 1.30–1.35, with 6–8 rounded angles in side view, not really nodulose, with relatively thick walls. Basidia 35–55 × 12–14 μm, 4-spored, clamped. Lamella edge fertile. Cystidia absent. Pileipellis a cutis with transition to a trichoderm of cylindrical hyphae, with terminal elements up to 15(20) μm wide. Pigment intracellular; subpellis not differentiated. Stipitipellis a cutis with scattered caulocystidia in groups at apex of stipe, cylindrical to clavate or ampulliform, 20–50 × 6–10 μm. Oleiferous hyphae present in trama. Clamp-connections present in all tissues.

Habitat and distribution: In groups in open xerophytic vegetation, such as grasslands, orchards, parks, broad-leaved forest verges, etc., on calcareous soil. So far recorded and ITS confirmed from Austria, Czechia, Denmark, France, Germany, Hungary, and Romania, probably widespread in temperate Central Europe; almost exclusively recorded in late winter or spring.

Additional material examined: Austria, Niederösterreich, Schwechat, 22 Mar. 2008, T. Barta, WU-Myc 28495. Denmark, Møn, Jydelejet, Møns Klint, 23 Apr. 2017, T. Kehlet & M. Vestergaard, DMS-9190832 (C – material has been insect eaten). France, Dept. Moselle, Racrang, A. Grobelny (L0607237). Germany, Hessen, Butzbach, Friedhof, 17 Mar. 2020, C. Manz & F. Hampe, aCM22 (B 70 0105493). Hungary, Veszprém, Öskü, in sandy pasture, 27 Oct. 2015, P. Finy, FP-2015-10-27-1; Békés, Gyula, under Gleditsia, I. Nagy, NI-2020-03; Békés, Hódmezővásárhely, Apr. 2023, Zs. Kovács, KZs-2003-05 (ELTE); Feb. 2024, Zs. Kovács, KZs-2024-008 (ELTE); Pest, Törökbálint, 4 Mar. 2024, Re. Molnár, MR-2024-03-04 (ELTE); Fejér, Velence, 26 Feb. 2024, P. Finy, FP-2024-02-26-1 (ELTE); Jász-Nagykun-Szolnok, Tószeg, on lawn, 24 Feb. 2024, E. Gulyás, DB-2024-02-24-1 (ELTE); Baranya, Pécs, 25 Febr 2024, D. Kutyáncsánin, Damir-1 (ELTE). Romania, Covasna, Sfântu-Gheorghe, on pasture, 14 Apr. 2023, J. Farkas, FJ-2023-04-14-1 (ELTE).

Notes: Entoloma opacum, like E. plebejum, often appears in winter and spring between February and May/June, but occasionally also in autumn, usually in rather exposed, thermophilic spots, like roadsides, orchards, grazed calcareous grassland, and the margins of broad-leaved forests (Battistin et al. 2013a). It clearly differs from E. plebejum by its rather stocky habit, with the stipe usually being shorter than the pileus diameter; the smaller, more isodiametrical spores, and the lack of cystidia. Macroscopically, it can be distinguished from vernal species within the E. clypeatum group by its dark, marbled pileus. Because the holotype is in bad condition it seemed sensible to designate an epitype with an ITS barcode. The epitype has been collected in the same geographical area as the type locality; for colour photos of the collection see Tejkal (2020).

Entoloma plebejum (Kalchbr.) Noordel., Persoonia 12: 462. 1985. MB 104249. Fig. 7A–D.

Fig. 7.

A–D. Entoloma plebejum (A, C, D. L0607303, epitype; B. L0607278). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E–H. Entoloma resutum (E, G, H. LE F-315862, neotype; F. L4402169). E, F. Habit. G. Basidiospores. H. Pileipellis. Photos: A, B by B. Dima; E by O. Morozova; F by M.E. Noordeloos; H by G.M. Jansen. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores), 40 μm (pileipellis).

Basionym: Agaricus plebejus Kalchbr., Icon. Sel. Hymenomomyc. Hung. (Budapest) 2: 22. 1874. MB 372215.

Synonym: Entoloma erophilum (Fr.) P. Karst., Bidrag. Kännedom Finlands Natur. Folk 32: 259. 1879. MB 202261.

Typus: Kalchbrenner (1874), Icon. Sel. Hymenomyc. Hung. (Budapest) 2: pl. 12, fig. 1., lectotype (designated here, MBT 10028190). Hungary, Komárom–Esztergom, Gerecse Mts, Tatabánya, Turul monument, in Quercus-Fraxinus forest, 25 Apr. 2021, A. Nagy & B. Dima, DB-2021-04-25-1 (epitype L0607303, designated here, deposited at L, MBT 10028191); ITS sequence, GenBank PX412058.

Description (amended here): Basidiomata mycenoid to tricholomatoid. Pileus 30–60 mm wide, conical then expanding to conico-convex or convex with slight umbo, sometimes with slightly depressed centre, with involute then straight margin, not hygrophanous, not translucently striate, brown to grey brown, uniformly coloured or slightly paler towards margin, entirely radially fibrillose-tomentose, becoming more radially fibrillose to rimose with age, micaceous in patches, sometimes squamulose at centre. Lamellae moderately distant (L = 25–40, l = 1–3), adnexed, sometimes deeply emarginate to almost free, triangular at first then ventricose or arcuate then segmentiform, often veined on sides, white or grey then greyish pink with concolourous, entire edge. Stipe 60–90 × 6–10 mm, cylindrical or with broadened base, sometimes flattened with longitudinal groove, pallid, creamy white when fresh, turning yellowish brownish with age, floccose when young, then silvery fibrillose striate, white tomentose at base. Context thin. Smell slightly farinaceous, taste not recorded. Basidiospores (90/8) (9.0–)10.5–14.5(–17.0) × 7.0–11.0 μm, on average 12.0–12.8 × 8.0–8.5 µm, Q = 1.10–1.70, Qav = 1.45–1.55, irregularly nodulose-angled in side view. Basidia 22–32 × 6–10 µm, 4- rarely also 2-spored, clamped. Cheilocystidia, if present then sparse or lacking, 35–100 × 5–20 × 2–9 µm, fusiform to slenderly lageniform. Pileipellis a cutis with transitions to a trichoderm, made up of cylindrical to inflated hyphae, 10–20 µm wide, with inflated terminal elements, 55–125 × 15–25 µm; pigment abundant, brown, intracellular, diffuse or granular. Stipitipellis a loose cutis of cylindrical hyphae, 4–11 µm, occasionally with clusters of cylindrical to subclavate caulocystidia. Clamp-connections present, but not at all septa.

Habitat and distribution: Solitary or in groups on various soil types (clay, sand) but usually more or less calcareous, also on humus rich soils, in broad-leaved or coniferous forests, and in open sand dunes, parks and gardens; spring and early summer, occasionally also in late autumn. Widespread in Europe, but not common. ITS sequence-verified collections were studied from France, Germany, Hungary, Norway, and The Netherlands.

Additional material examined: France, Calvados, Damblainville, Réserve naturelle nationale du coteau de Mesnil-soleil, 19 Nov. 2022, J. Lagrandie (herb. Boutard, L0607302). Germany, Sachsen, Hirschfelde, Neißetal, Restauration, alluvial area of the river bank, over slightly alkaline soil, with Fraxinus and Quercus, 15 Apr. 2017, A. Karich AK230817 (GLM-F139002). Hungary, Komárom–Esztergom, Vértes Mts, Várgesztes, in Fraxinus-Quercus forest, 13 Apr. 2019, B. Dima, DB15-19 (L0607278); Komárom–Esztergom, Vértes Mts, Szárliget, under Fraxinus and Crataegus, 21 Apr. 2023, L. Vajda & G. Mokánszki, VL-2023-04-21-2; Komárom–Esztergom, Gerecse Mts, Héreg, 20 May 2023, Gy. Vrba, VGy-2023-05-20 (Kaygusuz et al. 2024). Norway, Vestland, Hordaland, Tysnes, Kattenes, grassland in garden, 31 Oct. 2021, P. Fadnes, PF2140 (O-F-204290). The Netherlands, prov. Noord-Holland, Robbenoordbos, 5 Nov. 2013, N. Dam, MY958 (L0607255); prov. Flevoland, Lelystad, Jagersveld, 5 May 1984, G. Tjallingii-Beukers (L4402026); ibid., 4 July 1987, P.B. Jansen (L4402036).

Notes: Entoloma plebejum is morphologically easily identified on account of the mycenoid to tricholomatoid habit with shiny-micaceous, radially fibrillose pileus, large spores and sometimes prominent cheilocystidia. It is normally a vernal species and can be found from February to June and in late autumn (November). Entoloma triste is very similar, differing among other things by the lack of cheilocystidia. The phylogenetically distant E. brunneofibrillosum known from Hungary and the Mediterranean region of Turkey is morphologically rather similar but has much smaller spores (Kaygusuz et al. 2024).

Entoloma resutum (Fr.) Quél., Bull. Soc. Bot. France, Actual. Bot. 23: 326. 1877. MB 196455. Fig. 7E–H.

Basionym: Agaricus resutus Fr., Epicrisis Systematis Mycologici: 145. 1838. MB 461683.

Typus: Sweden, Jämtland, Krokom, Krokom Camping site near Östersund, 28 Aug. 2016, O. Morozova, M.E. Noordeloos & B. Dima (neotype LE F-315862, designated here, deposited at LE, MBT 10028192); ITS sequence, GenBank OL338296 (Reschke et al. 2022a).

Description (amended here): Basidiomata mycenoid to slenderly tricholomatoid. Pileus 10–30 mm wide, conical, then expanding to conico-convex or plano-convex, with or without small umbo, with inflexed then straight margin, not hygrophanous, not translucently striate, or rarely slightly translucently striate at margin, dark grey brown or sepia brown, uniformly coloured, not or only slightly paler towards margin, micaceous–radially fibrillose, with aeriferous fibrils, subtomentose, initially even slightly squamulose at centre, then radially fibrillose, finally splitting up in radial rows of fibrillose squamules, showing paler trama between the fibrils. Lamellae distant (L = 25–40, 1 = 1–5), thickish, narrowly adnate, ventricose, grey, then grey brown with pink tinge, paler towards the sub-entire to irregularly eroded edge. Stipe 20–45 × 3–6 mm, cylindrical to compressed with longitudinal groove, with slightly to distinctly broadened base, (grey) brown, paler than pileus, glabrous and polished or finely silvery fibrillose lengthwise, sometimes twisted, solid or fistulose. Context concolourous with surface in cortex, pale and fibrous in inner parts. Smell indistinct to distinctly farinaceous. Taste distinctly farinaceous-rancid. Basidiospores (45/3) 7.5–11.0(–12.0) × 5.5–8.0 μm, on average 9.5–10.2 × 6.7–7.4 μm, Q = 1.25–1.70, Qav = 1.35–1.45, irregularly, mostly 7-angled in side view. Basidia 27–40 × 8–11 μm, 4-spored, clamped. Lamella edge fertile. Cystidia absent. Hymenophoral trama regular made up of cylindrical hyphae. Pileipellis a trichoderm at centre, towards the margin a transition between a trichoderm and a cutis, made up of radially arranged, 10–23 μm wide, slightly inflated hyphae; pigment brown, intracellular. Stipitipellis a cutis of narrow cylindrical hyphae. Caulocystidia absent. Clamp-connections present in hymenium, elsewhere rare or absent.

Habitat and distribution: Terrestrial, among mosses in semi-natural grasslands and dune slacks in grey dunes, in calcareous grasslands in the lowlands, and in roadside verges in submontane, mixed Picea/Fagus forests. Widespread, but apparently rare everywhere. Sequence data available from Germany, Russia, Sweden and The Netherlands.

Additional material examined: Germany, Bayern, Erlangen, date unknown, G. Wölfel, MEN-14 (L0607239); Sachsen, Schöneck, road near Skislope, 24 Sep. 2022, A. Karich IHI-22Ent01 (GLM-F139798). Russia, Pskov Oblast, Pushkinogorsky District, vicinity of the Mikhailovskoye Village, roadside in a mixed forest, 11 Sep. 2018, O. Morozova, 6PG18 (LE F-344065). The Netherlands, prov. Friesland, Island of Terschelling, Dazenplak, 3 Nov. 1978, M.E. Noordeloos 842 (L4402169).

Notes: Since no original material exists, nor a plate to refer to as lectotype, we choose a neotype from Sweden to fix the current concept of Entoloma resutum. It is a relatively small, but compact, mycenoid to tricholomatoid species, with dark grey brown pileus and stipe, ventricose lamellae, fitting well with the protologue. Fries (1838, 1867) suggested that it is close to Agaricus jubatus and A. griseocyaneus, probably because of the robust mycenoid to tricholomatoid habit and fibrillose pileus. Due to the often nodulose spores, Noordeloos (1982) incorrectly assumed that A. resutus could be identical with E. hispidulum, a very different species in subgenus Leptonia (Morozova et al. 2014a). In contrast to some of its mainly vernal relatives, E. resutum is autumnal. The species was presented (including a photograph of the here selected neotype) under the provisional name E. aff. triste in Brandrud et al. (2018).

Entoloma sordidolamellatum Noordel. & Enderle, Z. Mykol. 61(2): 190. 1995. MB 413036. Fig. 8.

Fig. 8.

Entoloma sordidolamellatum (L0607636). A, B. Habit. C. Basidiospores. D. Stipitipellis. E, F. Pileipellis. Photos: S. Saitta. Scale bars: 1 cm (habit), 10 μm (spores), 20 μm (pileipellis).

Typus: Germany, Bayern, Neu-Ulm/Pfuhl, Gymnasiums-gelände, in lawn, 4 Oct. 1992, M. Enderle (holotype L0064321); ITS sequence, GenBank PX412019.

Description (amended here): Basidiomata collybioid. Pileus 30–50 mm wide, convex then plano–convex with flattened to umbilicate centre, sometimes with a small, low umbo, with deflexed then straight margin, within the central depression, slightly hygrophanous, not translucently striate, grey brown to pale brown, uniformly coloured, pallescent along radial streaks, entirely finely to strongly radially fibrillose to squamulose? Lamellae moderately distant (L = 30–40, l = 3–5), adnate–emarginate with large decurrent tooth, ventricose, up to 10 mm broad, grey with entire, paler edge. Stipe 15–70 × 3–6 mm, cylindrical or compressed, greyish brown, more or less concolourous with pileus, pruinose at apex, strongly fibrillose striate-pruinose all over, white tomentose at base. Context brown. Smell and taste farinaceous to rancid. Basidiospores (60/4) 6.5–10.0 × 5.5–7.5(–9.0) μm, on average 7.3–8.0 × 5.9–6.3 µm, Q = 1.00–1.30, Qav = 1.20–1.25, 6–7-angular, (sub)isodiametrical. Basidia 18–25(–35) × 8–11 µm, clavate, 4-spored, clamped. Lamella edge fertile. Cystidia absent. Pileipellis a cutis with transitions to a trichoderm of inflated elements, 80–150 × 20–40 µm, with abundant brown, intracellular pigment. Stipitipellis a loose cutis of cylindrical hyphae, 4–11 µm wide, with scattered, cylindrical to clavate terminal elements (“caulocystidia”), 20–60 × 4–11 µm. Clamp-connections present in all tissues.

Habitat and distribution: Terrestrial in small groups in open lawn on calcareous soil (holotype), on sandy soil in parks (Austria, Hungary), and in coastal dunes among mosses accompanied by Pistacia lentiscus, Eucalyptus globulus, and Pinus pinea (South Italy). Known from Austria, Germany, Hungary and Italy.

Additional material examined: Austria, Niederösterreich, Wiener Neustadt: Ortsgebiet, Schottergruben, in xerophytic grassland, 8 Sep. 1984, R. Schütz (WU-Myc 6732); LSU sequence, GenBank MK278035 (Varga et al. 2019); Niederösterreich, Wien, Lobau, in xerophytic grassland, 14 Jun. 1986, A. Hausknecht (L0607631). Hungary, Csongrád–Csanád, Szeged, Erzsébet-liget, on sandy soil, in park, under Quercus robur, 25 May 2019, B. Dima, DB-2019-05-25-1 (ELTE). Italy, Sicily, Messina, Laghetti di Marinello, Oliveri, on soil amongst moss in dune environment, 10 Dec. 2020, S. Saitta (L0607636).

Notes: Entoloma sordidolamellatum has long been known from the type-locality and one additional find in Austria only, but additional recent collections from Austria, Hungary and Italy helped us to position this species in sect. Erophila and made it possible to provide an amended description. It has been accommodated earlier in sect. Griseorubida subsect. Parvispora (Noordeloos 2004) on account of its collybioid habit, strongly radially fibrillose pileus, pileipellis with broad elements, intracellular pigment, presence of in all tissues, small spores and lack of cheilocystidia. Noordeloos (2004) pointed also to the similarity with E. farinasprellum, because of the strong farinaceous smell and the general colour. As became apparent from the present phylogenetic study, both E. sordidolamellatum and E. farinasprellum (as synonym of E. undulatosporum, see above), belong to the sect. Erophila. The rather small, more or less isodiametrical, and regularly shaped spores are distinctive. It could therefore be confused with E. sericeoides, which has, however, a smoother pileus, more 5-angled spores, and encrusting pigments in the pileipellis, and belongs to subgen. Claudopus (see below).

Entoloma triste (Velen.) Noordel., Persoonia 10: 254. 1979. MB 450879. Fig. 9.

Fig. 9.

Entoloma triste (A, C, D. L0607238, epitype; B. B 70 0105496). A, B. Habit. C. Basidiospores. D. Pileipellis. Photos: A by B. Dima; B by A. Gminder. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores), 20 μm (pileipellis).

Basionym: Nolanea tristis Velen., České Houby 3: 630. 1921. MB 280730.

Typus: Czechia, Bohemia, Krč, May 1920, J. Velenovský (holotype, PRC). Hungary, Budapest, Széchenyi-hegy, in calcareous dry grassland, 13 Nov. 2014, L. Albert & B. Dima, DB5690 (epitype L0607238, designated here, deposited at L, MBT 10028193); ITS sequence, GenBank PX412069.

Description (amended here): Basidiomata mycenoid to tricholomatoid. Pileus 20–40 mm, convex to plano-convex with distinct umbo, not hygrophanous or translucently striate, dark reddish brown to grey brown, towards margin often somewhat paler, radially fibrillose with paler fibrils on dark background, sometimes very finely squamulose all over. Lamellae moderately distant (L = 24–40, l = 3–7), whitish to pale brown at first, contrasting with pileus, then with pink tinge, with an entire, concolourous edge. Stipe 30–50 × 2–5 mm, cylindrical, pale brown, often much paler than pileus, distinctly fibrillose with paler longitudinally fibrillose covering. Context thin, concolourous. Smell and taste not distinctive. Basidiospores (50/3) 9.5–11.5(–12.0) × 6.0–7.5 μm, on average 10.4–11.2 × 6.7–7.0 μm, Q = 1.20–1.60, Qav = 1.25–1.35, nodulose-angular in side view. Basidia 29–48 × 7–11 μm, 4-spored, clamped. Lamella edge fertile. Cheilocystidia not observed. Hymenophoral trama regular, made up of medium-sized, cylindrical elements, 90–150 × 4–16 μm. Pileipellis a cutis with transitions to a trichoderm of 8–22 μm wide, cylindrical to subclavate elements; pigment intracellular, brown. Stipitipellis a loose cutis of narrow, cylindrical hyphae. Caulocystidia absent. Clamp-connections present.

Habitat and distribution: In small groups in exposed, xerophytic semi-natural grasslands, apparently mainly in continental, more or less steppe-like sites. Probably widespread in Central Europe, with an outpost in Northern Europe. ITS sequence verified from Germany, Hungary, Norway, and surprisingly New Zealand.

Additional material examined: Germany, Baden-Württemberg, Aschaffenburg, 17 Nov. 2021, A. Gminder, AG2021 (B 70 0105496). Hungary, Bács-Kiskun, Kecskemét, Méntelek, in pasture, 21 Apr. 2006, L. Nagy, NL-5190 (SZMC), LSU sequence, GenBank MK278015 (Varga et al. 2019). Norway, Innlandet, Oppland, Vågå, Sandehorten, calcareous dry meadow, near forest edge, 7 Sep. 2005, J.B. Jordal, JBJ-3030 (O-F-158210).

Notes: Entoloma triste is a small, robust mycenoid to tricholomatoid species, characterised by its umbonate pileus, and fibrillose stipe. Wölfel & Noordeloos (1997a) presented a wide concept of E. triste, including collections with the typical nodulose spores, and collections with angular spores. Now it appears that this concept is based on a mixture of different taxa. So, there is a need for an amended description. Since the holotype material is stored in liquid, and in a very poor state, it was decided to designate an epitype from Hungary, that fits the original diagnosis.

Entoloma umbrinotinctum Dima, Noordel., Benkő, E. Molnár & Vajda sp. nov. MB 860385. Fig. 10.

Fig. 10.

Entoloma umbrinotinctum (A, C, D. ME-2021-05-02, holotype; B, E. VL-2021-04-22). A, B, E. Habit. C, D. Basidiospores. Photos: A by Ru. Molnár; B, E by L. Vajda; D by E. Molnár. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores).

Etymology: umbrinus (Lat.) – umber brown, tinctus (Lat.) – coloured. Referring to the colour of the basidiomata.

Typus: Hungary, Veszprém, Bakony Mts, Bakonybél, on soil, under Fagus and Fraxinus, 2 May 2021, E. Molnár & Ru. Molnár, ME-2021-05-02 (holotype, L0607187); ITS sequence, GenBank PX412070.

Description: Basidiomata omphalinoid. Pileus 10–20 mm wide, convex-umbilicate with deflexed then straight margin, not hygrophanous, uniformly dark umber brown to blackish brown, covered with silvery radially arranged fibrils, translucently striate up to half the radius. Lamellae moderately distant (L = about 25–30, l = 1–3), adnate-emarginate with distinct decurrent tooth, initially greyish, then brownish-cream, later pinkish brown, with concolourous, eroded edge. Stipe 20–40 × 2–3, cylindrical, very dark brown like the pileus or slightly paler, pubescent when young, glabrescent with age and polished, at least in the upper part, basal part sometimes covered with white mycelium. Context concolourous with surface. Smell indistinct, taste not noted. Basidiospores (50/3) 7.5–12.0 × 4.0–9.5 μm, on average 10.0 × 6.7 µm, Q = 1.10–1.90, Qav = 1.35–1.5, nodulose-angular in side view with rounded angles, very irregularly shaped. Basidia 22–40 × 7–11 µm, 4- rarely 2-spored, clamped. Lamella edge fertile; cystidia not observed. Hymenophoral trama regular, made up of cylindrical elements, 50–160 × 4–12 µm. Pileipellis a cutis with transitions to a trichoderm, made up of cylindrical, 5–12 µm wide hyphae with cylindrical to inflated terminal elements, 40–110 × 5–18 µm; pigment brown. Stipitipellis a thin cutis of cylindrical, 4–12 µm wide hyphae; caulocystidia absent. Clamp-connections seen in hymenium, but elsewhere seemingly lacking.

Habitat and distribution: Two collections were found in alluvial forests with Fraxinus, Salix and/or Populus. One collection originates from a warmer/drier site with Quercus and Fraxinus, another one from a cooler/moister habitat with Fagus and Fraxinus. So far only known from a few localities in springtime from West, South and Northwestern Hungary.

Additional material examined: Hungary, Komárom-Esztergom, Vértes Mts, Szárliget, on soil, near Fraxinus, Quercus, 21 Apr. 2023, L. Vajda, VL-2023-04-21-3 (L0607188); Somogy, Belső-Somogy, Somogyudvarhely, on soil, in alluvial forest with Salix, Populus and Fraxinus, 22 Apr. 2021, L. Vajda, VL-2021-04-22 (ELTE); Vas, Sárvár, Szatmár-erdő, on soil, in alluvial forest, near Cornus mas, Fraxinus excelsior, Quercus, Juglans nigra, 7 May 2022, G. Benkő, K. Fábrics & R. Balka, BG-2022-05-07 (ELTE).

Notes: Entoloma umbrinotinctum is distinctive with its very dark and slender basidiomata (sometimes resembling E. politum from subgenus Entoloma), umbilicate pileus, relatively distant lamellae, and nodulose-angular, elongate spores.

Entoloma undulatosporum Arnolds & Noordel., Persoonia 10: 295. 1979. amend. MB 313841. Fig. 11.

Fig. 11.

Entoloma undulatosporum (A, C, D. L0607697; B. L0607427). A, B. Habit. C. Basidiospores. D. Pileipellis. Photos: A by H. Huijser; B by R. Enzlin; C, D by G.M. Jansen. Scale bars: 1 cm (habit), 10 μm (spores), 40 μm (pileipellis).

Synonym: Entoloma farinasprellum Arnolds, Biblioth. Mycol. 90: 329. 1982. MB 109414.

Etymology: The name refers to the undulate outline of the spores.

Typus: The Netherlands, prov. Drenthe, Beilen, along Linthorst-Homan Channel, in mossy short-grazed grassland on dry, acidic sandy soil, 11 Oct. 1976, E.J.M. Arnolds, Arnolds 3624 (holotype L0053513); ITS sequence, GenBank PX412020.

Description (amended here): Basidiomata collybioid. Pileus 5–30 mm wide, campanulate, conico–convex or convex then expanding, truncate with slightly to distinctly depressed centre, with incurved then deflexed margin, hygrophanous, when moist dark grey brown, sepia, or blackish brown, sometimes with a slight olivaceous tinge, often slightly paler at the margin, translucently striate at margin only or up to centre, pallescent on drying to grey brown, shining, finely radially fibrillose, fibrillose to minutely squamulose at centre. Lamellae moderately distant (L = 20–30, l = 1–3), broadly adnate with decurrent tooth or adnate–emarginate to narrowly adnate, segmentiform to ventricose, pale grey brown then sordid pinkish brown or pinkish grey, with entire, slightly paler or concolourous edge. Stipe 20–35 × 1–4 mm, cylindrical or compressed, brown or olivaceous brown, usually somewhat paler than pileus, glabrous, polished, white tomentose at base. Context very thin, concolourous with surface. Smell and taste indistinctive or distinctly farinaceous. Basidiospores (120/8) 7.5–11.0 × 5.5–7.0(–8.0) μm, on average 8–10 × 6–7 µm, Q = 1.20–1.70, Qav = 1.35–1.45, heterodiametrical, irregularly 6–8 to many-angled or nodulose in side view, very thin–walled, slightly cyanophilous. Basidia 20–60 × 6–11 µm, clavate or constricted-clavate, 4-spored, clamped. Lamella edge fertile. Cystidia absent. Hymenophoral trama regular, made up of more or less cylindrical elements, 50–120 × 7–16 μm. Pileipellis a cutis with transitions to a trichoderm, made up of cylindrical to inflated hyphae, 8–15 µm wide with inflated terminal elements, up to 25 µm wide; pigment brown, intracellular. Stipitipellis a cutis of cylindrical hyphae, 3.5–15 μm wide with pale yellow brown intracellular pigment; caulocystidia absent Clamp-connections usually abundant in hymenium, more scattered in all other tissues, exceptionally clampless (L0608395).

Habitat and distribution: Solitary or in small groups in semi-natural, xerophytic or moist grasslands and subalpine/subarctic heaths, from the lowland and Mediterranean up into the alpine zone, also in arctic sites (Norway, Svalbard), often in richer to calcareous soils (at least in northern regions). Widespread, from basidiomata data it is known from Denmark, Finland, Germany, Italy, Norway, Spain, Sweden, and The Netherlands, while based on environmental sequences E. undulatosporum occurs also in Estonia, Latvia, North Korea, Russia, and Pakistan.

Additional material examined: Finland, Outer Ostrobothnia, Rovaniemi, Muurola hospital area, grassland/lawn with Pinus, quite long continuity, 20 Sep. 2022, T. Kekki, Kekki3824 (L0607391). Germany, Mecklenburg-Vorpommern, Schlakendorf, Kiesgrube, 4 Nov. 2022, A. Karich (GLM-F139796). Italy, Tuscany, Castiglion Fiorentino, St. Stefano, 22 Oct. 2010, M. Dondl, MD5 (L0607300); Alto Adige, Roncegno, Cinque Valli, in mixed forest of Castanea and Carpinus, Sep. 1992, A. Hausknecht (WU-Myc 43609). Norway, Svalbard, Nordenskiöld Land, Hiorth hamn – Moskuslaguna, rich plain with moist places, grasses, Salix and Bistorta, 9 Aug. 2015, A. Molia, AM-35-2015 (O-F-260136). Spain, Mallorca, St. Elm, in Mediterranean shrub vegetation, 16 Dec. 2011, J. Kleine, F. Hampe, ENT11121601 (B 70 0105492). Sweden, Lule lappmark, Jokkmokk, Padjelanta NP, Arralåbddå, 11 Aug. 2016, J. Olsson, JO160811 (GB-0207762). The Netherlands, prov. Drenthe, Beilen, Smalbroek, in dry grassy heathland on acid, nutrient poor soil, Nov. 1976, J.M. Arnolds, Arnolds3750 (L053742, holotype of E. farinasprellum; ITS sequence, GenBank PX412014); prov. Noord-Brabant, Nuenen, along cycling path to Dierenrijk, 29 Oct. 2019, H. Huijser HU06 (L0607969); prov. Groningen, Wollinghuizen, Graveyard, 17 Oct. 2020 R. Enzlin ENZ200048 (L0607427).

Notes: The main characteristics of E. undulatosporum are the dark brown to almost black, often slightly to distinctly umbilicate pileus, the glabrous, polished stipe and the relatively small, thin-walled, many-angled spores with an undulate outline. Among the many collections labelled as E. undulatosporum, several other undescribed species appeared to be hiding after the molecular studies. Therefore, an amended description is made, based on sequence-verified material only. Entoloma farinasprellum, described from a similar habitat, appeared to be conspecific with the type of E. undulatosporum based on the analysis of the ITS sequences. This makes sense when comparing the original description. The epithet farinasprellum referred to the likeness with E. asprellum, a species in subgen. Cyanula, with a more or less similar habit and polished stipe, and the obvious farinaceous smell, which is unusual for Cyanula species (Noordeloos et al. 2022a). Entoloma griseopulchrum, described below, is rather similar, but differs by the umbonate pileus, fibrillose stipe, somewhat narrower spores and a distinct phylogenetic position.

/Alboleptonia clade – subgen. Alboleptonia

Entoloma subgen. Alboleptonia (Largent & R.G. Benedict) Noordel., Persoonia 10: 246. 1979. MB 860360.

Basionym: Alboleptonia Largent & R.G. Benedict, Mycologia 62(3): 439. 1970. MB 17036.

Synonym: Rhodophyllus subgen. Alboleptonia (Largent & R.G. Benedict) Romagn., Beih. Nova Hedwigia 59: 59. 1979. MB 860361.

Type species: Entoloma sericellum (Fr.) P. Kumm.

The /Alboleptonia clade coincides with the current morphology-based concept of subgenus Alboleptonia. The basidiomata of this clade are usually white or pale coloured, or with ochre yellow or pale brown tinges, some are pink. It is a diverse group and is widespread all over the globe (Largent & Benedict 1970, Romagnesi & Gilles 1979, Horak 1980, Noordeloos 1987, 1992, 2004, Manimohan & Leelavathy 1988, Baroni & Lodge 1998, Henkel et al. 2011, Reschke et al. 2022a). In Europe, at least 11 phylogenetic species are currently distinguished, of which six are described as new below. Entoloma sericellum is neotypified, and an amended description is given. While morphological separation of these whitish species is not always easy, the ITS barcode differences are often large, and is helpful for identification. The phylogenetic tree (Fig. 12) includes several extralimital species. So far, we have not seen any European species being recorded from other continents, but on the contrary, the extralimital species included usually form well-supported clades of their own.

Fig. 12.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma subgen. Alboleptonia (= /Alboleptonia clade). ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma albostriatum Brandrud, Noordel. & Dima, sp. nov. MB 860415. Fig. 13.

Fig. 13.

Entoloma albostriatum (A, C–F. O-F-254601, holotype; B. TEB 209-16). A, B. Habit. C, E. Cheilocystidia. D, F. Basidiospores. Photos: A, B by B. Dima; C, D by M.E. Noordeloos. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia).

Etymology: albus (Lat.) – white, striatus (Lat.) – translucently striate, referring to the white, translucently striate pileus.

Typus: Norway, Telemark, Porsgrunn, Kolbjørn-Frierflogene NW, on soil in calcareous Corylus-Fraxinus forest, 21 Sep. 2015, T.E. Brandrud & B. Dima, TEB 454-15 (holotype O-F-254601); ITS sequence, GenBank PX412021.

Description: Basidiomata minute, omphalinoid. Pileus 5–10 mm wide, convex then flattened, slightly to distinctly umbilicate, with deflexed margin, hygrophanous, white when moist or tinged pink, translucently striate to centre, becoming more or less opaque, dull-coloured upon drying, smooth, glabrous. Lamellae very distant (L = 14–20, l = 1–3), adnate-decurrent, white then pink with concolourous, entire edge. Stipe 20–25 × 1–2 mm, cylindrical, white, smooth, dull, not polished. Context very thin, brittle. Smell indistinct, taste not noted. Basidiospores (30/2) 9.5–15.0 × 7.0–9.0 μm, on average 12.40 × 7.80 μm, Q = 1.35–1.85, Qav = 1.50–1.60, heterodiametrical, irregularly 7–9-angled with blunt angles. Basidia 20–45 × 6–11 μm, 4- and 2-spored, clamped. Lamella edge heterogeneous with abundant, spread or clustered cheilocystidia, 40–80 × 4–10 μm, fusiform to lageniform, protruding from the hymenium. Hymenophoral and pileitrama regular, made up of short, inflated elements, 50–120 × 5–15 μm. Pileipellis a cutis of cylindrical, 5–15 μm wide hyphae, with scattered inflated terminal elements (“pileocystidia”), 40–70 × 7–17 μm. Pigment absent. Stipitipellis not observed. Clamp-connections rare, only seen in hymenium.

Habitat and distribution: So far known only from Denmark and Norway. The Norwegian collections were from margins of calcareous Corylus-Fraxinus and Pinus forests. The Danish collection grew on dead stems in an intensely studied coastal, scrubby plot (40 × 40 m) with more than 200 macro-fungal species recorded in three visits, hereof at least 19 species of Entoloma (T. Læssøe pers. comm.).

Additional material examined: Denmark, Sjælland, Eskebjerg Vesterlyng, Biowide 089, on rotten herbaceous stems in calcareous coastal scrub, 23 Sep. 2015, T. Læssøe, DMS-718433 (C). Norway, Telemark, Bamble, Røsskleiva NR north, grassy margin of calcareous Pinus forest, along small road (ski track), 14 Aug. 2016, T.E. Brandrud & B. Dima, TEB209-16 (O-F-254647).

Notes: Entoloma albostriatum is characterized by rather tiny, omphalinoid basidiomata, with hygrophanous, translucently striate pileus, large spores, and scattered large pileocystidia-like structures. It resembles E. percandidum, from which it differs by the much larger and almost nodulose-angular spores and presence of cheilocystidia. The lectotype of E. percandidum (Noordeloos 1987) has not successfully been sequenced, but Kokkonen (2015) got an ITS barcode of a later collection, mentioned in the protologue. This sequence, GenBank LN850602, is definitely different from that of E. albostriatum. The current status of E. percandidum, however, is poorly known due to the lack of well-documented and sequenced material. Entoloma olorinum sensu Noordeloos (1987) has some resemblance, but differs microscopically by the shorter, subisodiametrical spores and lack of cystidia. On the other hand, E. olorinum in the original sense (based on Rhodophyllus olorinus) was described as an Alboleptonia close to E. sericellum, but with a deeply translucently, striate pileus, slightly smaller, 5–6-angled spores and fertile lamella edge. A full description was given by Noordeloos (1987), based mainly on material from The Netherlands and Belgium. However, the lectotype of E. olorinum turned out to be identical with that of E. nidorosum from subgen. Entoloma, and probably represents a dwarfish, white form of that species. Since none of the collections cited by Noordeloos (l.c.) could be sequenced, it is hard to tell whether this concept of E. olorinum is homogeneous or a mixture of species. Among the species described in this paper, E. albostriatum comes closest, but has much larger spores and well-developed cheilocystidia.

Entoloma chioneum J.B. Jordal, Reschke, Noordel., E. Larss., Dima & N. Filippova, sp. nov. MB 860398. Fig. 14.

Fig. 14.

Entoloma chioneum (A. JBJ19-150, holotype; B, D–F. EL75-18; C. JBJ19-151). A–C. Habit. D. Cheilocystidia. E, F. Basidiospores. Photos: A–C by J.B. Jordal; D, E by G.M. Jansen. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores).

Etymology: χιών (Greek) – “snow”, referring to the white basidiomata, and occurrence in snow-rich, alpine habitats.

Typus: Sweden, Åsele lappmark, Vilhelmina, Frimtsjåkke, on soil in calcareous alpine heath, 22 Aug. 2019, J.B. Jordal & E. Larsson, JBJ19-150 (holotype GB-0107743); ITS sequence, GenBank PV018320.

Description: Basidiomata mycenoid to omphalinoid. Pileus 5–15 mm wide, conico-convex or hemispherical then convex, with blunt centre, white, not hygrophanous or translucently striate (when young), opaque, innately radially fibrillose, silky shining, becoming slightly pinkish yellow and translucently striate and glabrous with age. Lamellae very distant (L = 10–16, l = 3–7), adnate-decurrent, white then pink, with concolourous, subentire edge. Stipe 20–40 × 1–2(–3) mm, cylindrical, white, glabrous. Context thin, white, brittle. Smell and taste not noted. Basidiospores (200/18) 7.0–9.5(–10.0) × 5.5–8.0, on average 8.9–9.1 × 6.8–7.0 µm, Q = 1.05–1.50, Qav = 1.25–1.30, 5–6-angled in side view with regular angles. Basidia 20–36 × 6–12 µm, 4-spored, clamped. Lamella edge sterile or heterogeneous, with abundant subcylindrical to lageniform cheilocystidia, 35–65 × 4–10 µm. Hymenophoral trama regular, elements sausage-shaped, 40–110 × 5–20 µm. Pileipellis a thin cutis of cylindrical hyphae with inflated terminal elements, 4–14 µm wide; pigment absent. Stipitipellis a cutis of cylindrical 4–9 µm wide hyphae. Caulocystidia absent. Clamp-connections rare to abundant.

Habitat and distribution: In groups in montane and subarctic heathlands, alpine meadows with dwarf Salix and Betula nana. Mainly alpine, some middle-northern boreal; so far verified from North Sweden, North and South Norway and West Siberia.

Additional material examined: Norway, Innlandet, Oppland, Vang, gamle kongevei, moist margin of old track road with grass and herbs (middle/northern boreal zone), 16 Aug. 2019, E. Bendiksen, KB&EB 69/19 (O-F-256879); Nordland, Alstahaug, Tjøtta, calcareous semi-natural grassland, 29 Aug. 2020, J.B. Jordal, JBJ20-E22 (O-F-260819); Troms, Karlsøy, Reinøya, Nordeidet, grazed mountain slope, 21 Aug. 1999, V. Ravolainen, VTR 88-99 (TROM-F-610271); Troms, Kåfjord, Manndalen, Lilledalen, low herb birch forest, 24 Jul. 2022, G. Gaarder & J.O. Olsen, GG8096 (O-F-259693); Trøndelag, Steinkjer, Kvamshaugen, Ryggadalen, margin of forest road, 20 Aug. 2016, E. Bendiksen & B. Dima, EB 82/16 (O-F-253827); Trøndelag, Sør-Trøndelag, Oppdal, Søndre Knutshø, calcareous alpine heath, 15 Aug. 2020, G. Gaarder & P.G. Larsen, GG7827 (O-F-260877). Sweden, Pite Lappmark, Arjeplog, west of Nuorta Krapesvarre, in rich alpine vegetation, 12 Aug. 2018, J.B. Jordal & E. Larsson, EL75-18 (GB-0207756) – ITS sequence, GenBank PV018334; Pite Lappmark, Arjeplog, NE side of Mt. Ákháris, alpine meadow on calcareous soil, 14 Aug. 2018, J.B. Jordal & E. Larsson, EL144-18 (GB-0207754); ibid., J.B. Jordal & E. Larsson, EL150-18 (GB-0207753); Pite Lappmark, Arjeplog, Rijvatahkka, 15 Aug. 2018, E. Larsson, EL201-18 (GB-0207750); Åsele lappmark, Vilhelmina, Lasterfjället, Tjårronunjes, in alpine meadow on calcareous ground, 19 Aug. 2019, J.B. Jordal, JBJ19-101 (GB-0207757); ibid., J.B. Jordal, JBJ19-110 (GB-0207755); Åsele lappmark, Vilhelmina, Murfjället, in alpine heath on calcareous ground, 20 Aug. 2019, J.B. Jordal, JBJ19-125 (GB-0207758); ibid., J.B. Jordal, JBJ19-132 (GB-0207747); ibid., J.B. Jordal, JBJ19-135 (GB-0207741); Åsele Lappmark, Vilhelmina, Frimtsjakke, in low alpine vegetation on calcareous soil, 22 Aug. 2019, J.B. Jordal, JBJ19-151 (GB-0207759); Jämtland, Frostviken, NW slope of Raavre, in low alpine calcareous heath 23 Aug. 2019, J.B. Jordal, JBJ19-162 (GB-0207748); ibid., J.B. Jordal, JBJ19-172 (GB-0207751); ibid., J.B. Jordal, JBJ19-174 (GB-0207749); ibid., J.B. Jordal, JBJ19-184 (GB-0207752); Västernorrlands län, Kullen mountain, on soil in oligotrophic grassland grazed by sheep, 26 Aug. 2018, K. Reschke, KaiR1203 (M); ibid., KaiR1214 (M). Russia, Khanty-Mansi Autonomous Okrug, Khanty-Mansiysk District, near Shapsha Village, on soil in mixed shrub vegetation and poorly developed undergrowth, 28 Jul. 2015, N. Filippova, YSU-F-05621 (dupl. LE F-343351).

Notes: Entoloma chioneum differs from E. sericellum particularly by the initially purely white, but later slightly yellowish-ochre tinged, innately fibrillose pileus, and somewhat smaller, 5–6-angled spores. It is the most common Alboleptonia in alpine regions of Northern Europe and seems to be a mainly (but not strictly) northern species, growing in alpine and mostly northern boreal localities in northern and central parts of Norway and Sweden. It has never been found in the rather well investigated areas of South Scandinavia. In addition, there is one sequence-verified record from the Siberian taiga.

Entoloma eborinum J.B. Jordal, O.V. Morozova, Reschke, Noordel., Bendiksen & Dima, sp. nov. MB 860410. Fig. 15.

Fig. 15.

Entoloma eborinum (A. JBJ21-101; B. JBJ22-230; C–E. O-F-76838, holotype). A, B. Habit. C. Basidiospores. D, E. Cheilocystidia. Photos: A, B by J.B. Jordal; E by M.E. Noordeloos. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia).

Etymology: eborinus (Lat.) – referring to the ivory-coloured pileus.

Typus: Norway, Trøndelag, Sør-Trøndelag, Ørland, Tarva, Været, on soil in calcareous, semi-natural pasture, 25 Sep. 2020, J.B. Jordal, JBJ20-E83 (holotype O-F-76838); ITS sequence, GenBank PX412033.

Description: Basidiomata collybioid. Pileus 10–15 mm wide, convex to plano-convex, ivory to flesh coloured, somewhat hygrophanous, pallescent from the margin, bicoloured, centre may retain the original darker colour for a longer time, and there may also be a transitional phase with concentric paler and darker zones, never translucently striate, smooth, glabrous. Lamellae rather distant (L = 20–25, l = 3–5), adnate to adnate-decurrent, white then pink with a more or less serrulate, concolourous edge. Stipe 20–40 × 1–2.5 mm, cylindrical, glabrous, polished. Context brittle. Smell indistinct, taste not noted. Basidiospores (140/10) 7.5–11.0 × 6.0–7.5 μm, on average 9.0–9.6 × 6.9–7.1 µm, Q = 1.20–1.60, Qav = 1.30–1.40 heterodiametrical, 5–6-angled in side view. Basidia 25–41 × 6–10 µm, 4-spored, clamped. Lamella edge sterile. Cheilocystidia subcylindrical to narrowly clavate or lageniform, 25–45 × 6–10(–15) µm, about as long as the basidia. Hymenophoral- and pileitrama regular, made up of cylindrical to slightly inflated (sausage-shaped) elements, 35–110 × 5–20 µm. Pileipellis a narrow cutis of cylindrical hyphae, 5–15 µm wide, without visible pigmentation. Clamp-connections present but sparse – in all tissues.

Habitat and distribution: In semi-natural pastures on calcareous soil, sometimes also in natural, calcareous, shallow soil grasslands, also recorded in alpine calcareous heath and along a riverbank. So far known from Norway, Sweden, Germany and the Russian Far East (Kamchatka). Apparently not rare in Scandinavia. The wide variation in recorded habitats indicates that this species probably has a much wider geographical distribution and, in the past, it might have been recorded as E. sericellum coll.

Additional material examined: Germany, Hessen, Goldsteintal, near Wiesbaden, on soil in oligotrophic grassland, 12 Nov. 2022, K. Reschke, KaiR1641 (B 70 0105523); ibid., 28 Oct. 2023, KaiR1788 (B 70 0105526); ibid., 28 Oct. 2023, KaiR1800 (B 70 0105527). Norway, Oslo, Bygdøy, Rodeløkken, open calcareous meadow on shallow soil, 31 Aug. 2017, E. Bendiksen, 162/17 (O-F-254463); Telemark, Porsgrunn, Heistad, Lundebukta, open calcareous meadow on shallow soil, 11 Oct. 2013, A. Molia & T. Læssøe, AM-252f-2013 (O-F-21944); Vestland, Hordaland, Bømlo, Brandasund, semi-natural grassland, 29 Sep. 2021, J.B. Jordal & P. Fadnes, JBJ21-105 (O-F-261059); Vestland, Hordaland, Stord, Hovaneset, calcareous semi-natural grassland, 28 Sep. 2021, J.B. Jordal & P. Fadnes, JBJ21-101 (O-F-261057); Vestland, Hordaland, Stord, Nautøya, on soil in coastal grassland, 6 Sep. 2019, K. Reschke, KaiR1377 (B 70 0105518); Vestland, Sogn og Fjordane, Luster, Hymavollen, semi-natural grassland, 9 Oct. 2021, J.B. Jordal, JBJ21-110 (O-F-261061). Russia, Kamchatka Krai, Bystrinsky District, near Esso Village, right bank of the Bystraya River, on grassland, 12 Aug. 2005, O. Morozova, 193KA05 (LE F-344067). Sweden, Åsele Lappmark, Vilhelmina, Lasterfjället, Tjårronunjes, calcareous alpine heath, 19 Aug. 2019, Å. Kruys, JBJ19-118 (GB-0207744).

Notes: Entoloma eborinum resembles E. sericellum and can be distinguished by the often rather smooth pileus that is ivory to pale flesh coloured when fresh, a polished stipe, small, 5–6-angled spores and a sterile lamella edge with rather inconspicuous cheilocystidia.

Entoloma ermineum J.B. Jordal, O.V. Morozova, Noordel. & Dima, sp. nov. MB 860419. Fig. 16A–C, E.

Fig. 16.

A–C, E. Entoloma ermineum (A, C, E. O-F-76839, holotype; B. L0607819). A, B. Habit. C. Cheilocystidia. E. Basidiospores. D, F, G. Entoloma nix (JBJ 19-139, holotype). D. Cheilocystidia. F. Basidiospores. G. Habit. Photos: A, G by J.B. Jordal; B by M. Jagers; E, F by M.E. Noordeloos. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia).

Etymology: ermineus (Lat.) – white with a touch of yellow, reminiscent of the cap-colour of Lepiota erminea.

Typus: Norway, Møre & Romsdal, Smøla, Jostøløya, on soil in semi-natural grassland, 30 Sep. 2020, J.B. Jordal, JBJ20-E92 (holotype O-F-76839); ITS sequence, GenBank PX412034.

Description: Basidiomata collybioid. Pileus 5–20 mm wide, conical, campanulate to hemispherical then convex with deflexed margin, with blunt centre, not hygrophanous or translucently striate, white, sometimes with a yellowish hue, particularly at centre, finely felted all over. Lamellae distant (L = 16–20, l = 1–3), adnate with decurrent tooth, white then pink with concolourous edge. Stipe 20–60 × 1–2 mm, cylindrical, white, dull, glabrous, apex somewhat pruinose as seen in images. Context thin, brittle. Smell indistinct, taste not noted. Basidiospores (80/5) 8.5–11.0 × 6.5–8.0 μm, on average 10.0–10.7 × 7.2–7.4 μm, Q= 1.20–1.55, Qav = 1.35–1.40, heterodiametrical, 6–7- angled in side view, with pronounced angles. Basidia 30–37 × 10–11.5 μm, clavate, 4-spored, clamped. Lamella edge heterogeneous. Cheilocystidia 25–65 × 5–18 μm, cylindrical, fusiform, scarce, in tufts. Pileipellis a cutis of cylindrical, 3–18 μm wide hyphae, with some subclavate, up to 20 μm wide terminal elements. Stipitipellis cutis of cylindrical, 4–10 μm wide, clamped hyphae. Caulocystidia in tufts at top of stipe, 60–90 × 8–17 μm, cylindrical, some with broadened apex, subclavate, clamped. Clamp-connections present in all tissues.

Habitat and distribution: On soil in semi-natural pastures, from coastal lowlands (West Europe) up into the subalpine zone (Central and Southeast Europe). Known from Austria, Norway, The Netherlands, and Russia (Caucasus).

Additional material examined: Austria, Vorarlberg, Kleinwalsertal, Walmendinger Horn, 17 Sep. 2018, K. Reschke, KaiR1341 (B 70 0105516); ibid., Moosalpe, edge of a wet meadow, 16 Sep. 2018, S. Sarawi, KaiR1329 (B 70 0105515); Vorarlberg, Schwarzwasserbachtal, 23 Oct. 2017, K. Reschke, KaiR941 (B 70 0105506). Norway, Møre & Romsdal, Smøla, Jostøløya, semi-natural grassland, 30 Sep. 2020, J.B. Jordal, JBJ20-E101 (O-F-76840); Vestland, Sogn & Fjordane, Kinn, Refvika, medium calcareous, semi-natural grassland, 25 Sep. 2019, J.B. Jordal, JBJ19-064 (O-F-256800). Russia, Karachaevo-Cherkesia Republic (Caucasus), Teberda State Biosphere Reserve, Malaya Khatipara Mt, in grassland, 14 Aug. 2009, O. Morozova, 156TB09 (LE F-254362) (Morozova et al. 2014b, as E. sericellum). The Netherlands, prov. Overijssel, Weerselo, Lemselermaten, wet grassland on peaty soil, 16 Oct. 2019, M. Jagers, MJD19032 (L0607819).

Notes: Entoloma ermineum morphologically is very similar to E. sericellum, differing by the smoother cap surface. Both species appear to have approximately the same habitat-range. However, phylogenetically they are rather distant, and E. ermineum is more related to E. confusissimum, recently described from Panama (Reschke et al. 2022a) and an undescribed species from the USA (Fig. 12).

Entoloma nix Dima, J.B. Jordal, E. Larss., Noordel. & M. Palamarchuk, sp. nov. MB 860420. Fig. 16D, F, G.

Etymology: nix (Lat.) – snow, referring to the white basidiomata, and occurrence in alpine, snow-rich sites.

Typus: Sweden, Åsele lappmark, Vilhelmina, Fiehteres, on soil in calcareous, alpine heath, 21. Aug. 2019, J.B. Jordal & E. Larsson, JBJ19-139 (GB-0207745); ITS sequence, GenBank PV018336.

Description: Basidiomata collybioid. Pileus 10–15 mm wide, hemispherical then convex, not hygrophanous, or translucently striate, white with slight ochre yellow tinge at centre, minutely felted, subglabrous. Lamellae distant (L = about 20, l = 1–3), arcuate-decurrent, initially pallid whitish cream then pink, with an entire, concolourous edge. Stipe 20–30 × 1–2 mm, cylindrical, white, minutely pruinose at apex, downwards smooth. Context brittle, concolourous with surface. Smell indistinct, taste not noted. Basidiospores (30/2) (8.0–)8.5–11.0 × 6.5–8.0 μm, on average 8.9–10.0 × 7.0–7.2 μm, Q = 1.20–1.50(–1.65), Qav = 1.15–1.45, 5–7-angled in side view with sharp angles. Basidia 23–40 × 6–11 μm, 4-spored, clamped. Lamella edge mostly sterile with dense clusters of cylindrical to lageniform or clavate cheilocystidia, 25–42 × 7–14 μm. Pileipellis a cutis of rather narrow, cylindrical, 6–15 μm wide hyphae, with scattered clavate terminal elements, 25–40 × 15–20 μm. Stipitipellis a cutis of narrow, cylindrical hyphae. Caulocystidia at apex of stipe only, cylindrical with rounded apex, 20–35 × 5–9 μm. Pigment absent. Clamp-connections present, but scarcely present, at least in hymenium, elsewhere not observed.

Habitat and distribution: In calcareous alpine grasslands, also found in pioneer vegetation along a riverbank. Known from North Italy, North Russia (Subpolar Ural Mountains), and North Sweden.

Additional material examined: Italy, South Tyrol, Solda, Madritsch, on soil in alpine environment, 29 Jul. 2018, B. Dima, DB-2018-07-29-3 (ELTE). Russia, Komi Republic, Intinsky District, Yugyd Va National Park, valley of the Khambaliyu River, river bank, on moss curtain, 20 Jul. 2012, M. Palamarchuk, SYKOf1707 (LE F-344075) (as E. percandidum, Palamarchuk 2016).

Notes: We have only very limited material of this species. The range of the spore size is the same as in E. sericellum, but the structure of the lamella edge differs by being (almost) entirely sterile with rather short cheilocystidia, similar to those found in the phylogenetically distant E. eborinum. In habitat preferences, E. nix resembles the mainly alpine E. chioneum, but this also possesses longer cheilocystidia and is also phylogenetically distant. Phylogenetically, E. nix belongs to a lineage with two species from Panama (E. amistadosericellum, E. nubilosilvae; Reschke et al. 2022a) and two yet unnamed species from the USA (Fig. 12).

Entoloma percandidum Noordel., Nordic J. Bot. 2(2): 161. 1982. MB 110654.

Replaced synonym: Rhodophyllus omphaliiformis Romagn. Rev. Mycol. (Paris) 19(1): 7. 1954. MB 528890, non Entoloma omphaliiforme (Velen.) Noordel., Persoonia 10(2): 262. 1979. MB 535080.

Typus: France, Seine & Oise, Chaumontel, La Charbonnière, in a marsh, 20 Aug. 1946, H. Romagnesi, Romagnesi 46.269 (lectotype in PC, designated in Noordeloos 1987, not sequenced).

Description (based on lectotype and Noordeloos 1987): Basidiomata omphalinoid. Pileus 4–10 mm wide, convex at first, often somewhat truncate, then expanding, but never entirely applanate, often with irregularly, undulating margin, hygrophanous, when moist deeply translucently striate, brilliantly white, opaque on drying, sometimes with slight yellow tinge with age, glabrous, finely satiny fibrillose when dry. Lamellae distant (L = 10–16, l = 1–3), often thick, adnate, sometimes emarginate or subdecurrent, triangular then segmentiform or subventricose, white then pink with entire, concolourous edge. Stipe (13–)24–45 × 0.5–2 mm, cylindrical, straight or somewhat flexuose, white, shiny, often hyaline and tinged yellow with age. Context very thin, brittle. Smell indistinct, taste not noted. Basidiospores (30/2) 7.0–11.5 × 5.5–8.0 μm, on average 9.5 × 7.0 µm, Q = 1.20–1.65, Qav = 1.4, 6–10-angled in side view. Basidia 4-spored, clamped. Lamella edge fertile, cystidia absent. Pileipellis a cutis of narrow, cylindrical hyphae. Clamp-connections present in hymenium.

Habitat and distribution: On soil in damp places in forests, and in semi-natural grassland. In Europe, but distribution is unknown.

Additional material examined: France, Seine & Oise, Chaumontel, marshy wood, 18 Aug. 1951, Robert & Causse, herb. Romagnesi 51179 (PC); ITS sequence, GenBank LN850602 (Kokkonen 2015).

Notes: We have not seen recent material of this species, therefore we refer to Noordeloos (1987). Kokkonen (2015) studied original material of R. omphaliiformis in PC, and obtained an ITS sequence of a later collection from the type locality, but unfortunately not from the lectotype. Entoloma percandidum resembles E. albostriatum that differs in having pure white basidiomata, reminiscent of a Hemimycena, smaller spores and no cheilocystidia, and a distant phylogenetic position.

Entoloma sericellum (Fr.) P. Kumm., Der Führer in die Pilzkunde: 97. 1871. MB 225035. Fig. 17.

Fig. 17.

Entoloma sericellum (A, D, E. O-F-304566, neotype; B. LE F-344070; C. LE F-311812). A–C. Habit. D. Basidiospores. E. Cheilocystidia. Photos: A by B. Dima; B, C by O. Morozova. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores).

Basionym: Agaricus sericeus ß sericellus Fr., Observ. Mycol. (Havniae) 2: 145. 1818. MB 462569.

Typus: Holotype not existing. Norway, Innlandet, Hedmark, Alvdal, at roadside South of Alvdal, 20 Aug. 2016, E.A. Thomsen (neotype O-F-304566, designated here, deposited at O, MBT 10028204); ITS sequence, GenBank PX412066.

Description: Basidiomata mycenoid to collybioid. Pileus 5–20 mm wide, hemispherical then expanding, with inflexed to deflexed margin, not hygrophanous, not translucently striate, white with yellow ochre tinge at centre, very finely felted to subsquamulose. Lamellae distant (L = 30–40, L = 3–7), adnate with decurrent tooth, purely pink with concolourous, entire edge. Stipe 20–40 × 1–2 mm, cylindrical, white to yellowish, pruinose at apex, more or less glabrous and polished below. Context thin, brittle, white. Smell and taste indistinct. Basidiospores (200/15) 9.5–14.0 × 7.0–9.5 μm, on average 10.6–11.7 × 7.8–8.3 μm; Q = 1.15–1.70, Qav = 1.35–1.40, heterodiametrical, 5–7-angled in side view with pronounced angles. Basidia 33–40 × 9.5–12 μm, 4-spored, clamped. Lamella edge heterogeneous. Cheilocystidia 35–50 × 7–11.5 μm, cylindrical, fusiform to lageniform, clamped. Hymenophoral trama and pileitrama regular, made up of sausage-shaped elements, 45–120 × 5–20 μm. Pileipellis is a transition between a cutis and a trichoderm, made up of cylindrical to slightly inflated hyphae, with cylindrical to clavate terminal elements, 25–90 × 7–20 μm; pigment absent or very pale brown, intracellular. Caulocystidia 20–50 × 5–12 μm, subcylindrical to flexuous, mainly present at apex of stipe. Clamp-connections present in all tissues.

Habitat and distribution: In groups in calcareous and more oligotrophic, semi-natural grasslands, sometimes also in calcareous broad-leaved and pine forests, alpine heaths and road verges. Common and widespread in northern and temperate Eurasia.

Additional material examined (selection): Finland, Ostrobottnia kajanensis, Suomussalmi, ca. 7 km NW of Kiannanniemi, NW of Petaejaevaara, N of the roadcross, on peaty soil, 27 Aug. 2011, J. Vauras, FIPUT323-14 (TUR190987). Germany, Thüringen, Arlesberg, Geratal, Schuchardswiese, on soil in nitrogen-poor grassland with abundant Meum athamanticum and Plantago lanceolata, 3 Nov. 2021, K. Reschke, KaiR1541 (B 70 0105522). Norway, Møre og Romsdal, Giske, Vigra: Molnes, semi-natural pasture, calcareous, 14 Sep. 2020, J.B. Jordal, JBJ20-E70 (O-F-261313); Møre og Romsdal, Sunndal, Jordalsøra, semi-natural grassland, mown, 20 Sep. 2019, J.B. Jordal, JBJ19-047 (O-F-256790); ibid., Mogstad, Stortrøa, semi-natural grassland, 1 Oct. 2022, J.B. Jordal, JB22-165 (O-F-259800); ibid., Tingvoll, Åkerfallet, semi-natural grassland, 13 Sep. 2021, J.B. Jordal, JB21-48 (O-F-261033); Nord-Trøndelag, Frosta, Tautra, Kuøra, semi-natural pasture, 31 Aug. 2020, J.B. Jordal, JBJ20-E64 (O-F-260851); Nordland, Alstahaug, Alstahaug: Tjøtta, semi-natural pasture, 29 Aug. 2020, J.B. Jordal, JBJ20-E32 (O-F-260825); Rogaland, Suldal, Suldal, Tveit, semi-natural pasture, 15 Sep. 2017, J.B. Jordal, JBJ17-2547 (O-F-254436); Trøndelag, Trøndelag, Sør-Trøndelag, Rennebu, Aunan, Lønshaugen, semi-natural pasture, 16 Sep. 2021, J.B. Jordal & S. Vatne, JB21-71 (O-F-261046); Vestland, Hordaland, Stord, Nautøya, calcareous, grazed near-shore grassland with shell-bed, 6 Sep. 2019, S. Weseth & T.E. Brandrud, NMC2019-124 (O-F-256419); Vestland, Hordaland, Bømlo, Lykling, Blyttarstemma, calcareous semi-natural pasture, 7 Oct. 2022, J.B. Jordal, P. Fadnes & A.H. Abaz, JB22-214 (O-F-259831). Russia, Altai Republic, near Gorno-Altaisk, on soil on ski slope, 1 Sep. 2018, O. Morozova, 115AL18 (LE F-344072); Altai Republic, Altaisky Nature Reserve, Teletskoye Lake shore, cordon Kokshi, on soil in grassland, 31 Aug. 2018, T.E. Brandrud, 111AL18 (LE F-344073); Komi Republic, Troitsko-Pechorsky District, Pechoro-Ilychscky Nature Reserve, Yaksha Village, on soil on grassland, 31 Aug. 2011, M. Palamarchuk, SYKOf1706 (LE F-344074); Primorsky Krai, Sikhote-Alin’ Nature Reserve, near Maisa forest station, on soil in mixed forest, 27 Aug. 2013, O. Morozova, 224CA13 (LE F-344068); Irkutsk Oblast, Bratsky District, near Kob’ Village, on sandy soil in grassland, 20 Aug. 1983, A.N. Petrov, 83-8-117 (LE F-18419); Leningrad Oblast, Tosnensky District, near stop platform 104 km of the St Petersburg–Veliky Novgorod railway line, on soil in grassland, 21 Aug. 1999, O. Morozova, 59TO99 (LE F-215485); Murmansk Oblast, Khibiny Mountains, valley of the Vudyavr Lake, south bank, on soil in the dwarf birch-heather tundra, 10 Aug. 1974, L.V. Mikhailovsky (LE F-9170); ibid., valley of the Imandra Lake, on soil on the roadside, 25 Aug. 2023, Yu. Rebriev, 76AP23 (LE F-344070); Sverdlovsk Oblast, Prigorodny District, Visimsky Nature Reserve, near Big Galashki Village, on clay soil in the young pine forest, 3 Sep. 2002, L.V. Marina, LE F-258122; Tver Oblast, Zubtsov District, 2 km SE of Mozgovo Village, open place in calcareous pine forest, right bank of the Derzha River, 11 Sep. 2015, O. Morozova, 42TV15 (LE F-311812); Vologda Oblast, Kirillovsky District, Russian North National Park, Calamagrostis meadow with sparse pine undergrowth, 8 Sep. 2005, O. Shiryaeva (LE F-235260); St Petersburg, near Komarovo Village, bank of the Shchuchye Lake, open place in the pine forest, 19 Sep. 2020, O. Morozova, 12LO20 (LE F-344069). Spain, Catalunya, Comarca Ripollès, Núria, vora Santuari, Parc Natural de les Capçaleres del Ter I del Freser, 27 Aug. 2014, J. Vila, O. Morozova, JVG 1140827-4 (LE F-312460); Catalunya, Comarca Pallars Sobirà, Espot, Parc Nacional d’Aigüestortes i Estany de Sant Maurici, Port de la Bonaigua, 24 Aug. 2014, J. Vila, X. Llimona & O. Morozova, JVG 1140824-22 (LE F-312459). The Netherlands, prov. Gelderland, Staverden, Leemputten, on soil in moist, Molinia-rich grassland on loamy, calcareous soil, 22 Oct. 2019, F. Salzmann & R. Salzmann (L0607705).

Notes: The concept of E. sericellum is now fixed with a neotype and a derived ITS. This was necessary considering the extensive diversity revealed in our studies, with a dozen of similar looking, but morphologically and phylogenetically different species. Those that have sufficient data are described here as new species. Entoloma sericellum is a species with a white pileus, which is soon tinged yellow and often turns entirely yellowish ochre with age. Its surface is entirely fibrillose to minutely squamulose but not translucently striate. It has pure white lamellae turning pink from spores and a glabrous, whitish to yellowish ochre stipe (see description above). Microscopically, it is characterised by the relatively large, heterodiametrical spores and scattered, subcylindrical to lageniform cheilocystidia, which are much longer than the basidia. In Norway, E. sericellum is distributed up to the northern boreal zone and is mainly found in semi-natural grasslands. It is probably the most common species in the group in semi-natural grasslands also in temperate and central Europe, but this needs to be verified with more well-documented material, considering the morphological diversity in this group. In particular, the distributional, morphological and ecological differences between it and the very similar, but phylogenetically very distant E. ermineum need to be evaluated. Geographical and ecological factors might also have been of importance for speciation in this clade. Entoloma chioneum seems to be the most common Alboleptonia in the northern, subarctic/alpine parts of Scandinavia, whereas other taxa have a more southern distribution. But conclusions can only be drawn when much more data is assembled. Entoloma sericellum generally is considered a species easy to identify in the field. Nothing could be further from the truth. Hopefully this study stimulates more critical collecting and sequencing of small, whitish Entoloma species.

Entoloma skadiae J.B. Jordal, Noordel., Reschke & Dima, sp. nov. MB 860399. Fig. 18.

Fig. 18.

Entoloma skadiae (O-F-256757, holotype). A, B. Habit. C. Cheilocystidia. D. Basidiospores. Photos: J.B. Jordal. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia).

Etymology: Named after “Skadi”, or “Skade” (old Norse Skaði), the goddess of winter, hunting and skiing; referring to the currently known distribution in Norway and the snow-white basidiomata.

Typus: Norway, Møre & Romsdal, Sunndal, Jordalssjøen, on soil in mown, semi-natural meadow, 15 Oct. 2018, J.B. Jordal, JBJ18-120 (holotype O-F-256757); ITS sequence, GenBank PX412068.

Description: Basidiomata collybioid; rather compact and sturdy with a relatively thick stipe. Pileus 15–20 mm wide, campanulate with irregular wavy-lobed margin, not hygrophanous or translucently striate, white, matt, finely tomentose all over. Lamellae moderately distant (L = about 30, l = 1–5), deeply emarginate, almost free, thickish, sometimes anastomosing, white then pale pink with thickish, concolourous edge. Stipe 25–70 × 3–5 mm, white, absolutely glabrous, matt, not polished. Context thin, brittle, white. Smell indistinct, taste not noted. Basidiospores (30/2) 9.0–13.5 × 6.0–10.0 μm, on average 11.2–11.4 × 8.1–8.3 μm, Q = 1.20–1.65, Qav = 1.35–1.40, 6–7-angled in side view, with pronounced angles. Basidia 21–40 × 7–14 μm, 4-spored. Lamella edge heterogeneous. Cheilocystidia 50–100 × 7–15 μm, long, filiform-cylindrical to narrowly lageniform. Pileipellis a thin, loose cutis with transitions to a trichoderm of narrow hyphae, about 5 μm wide; no pigment detected. Pileitrama made up of short elements. Stipitipellis a cutis of narrow, cylindrical hyphae, 5–9 μm wide. Clamp-connections present.

Habitat and distribution: In semi-natural grassland. So far only known from two localities in Northwestern Norway.

Additional material examined: Norway, Trøndelag, Sør-Trøndelag, Hitra, Hifjellet south, on soil in weakly calcareous, moist forest meadow, 13 Sep. 2021, G. Gaarder & K. Svingen, GG7959 (O).

Notes: Entoloma skadiae is distinctive because of the sturdy stature for the group, white basidiomata, thin pileipellis, large spores and scattered, long cheilocystidia. The relatively large spores and long protruding cheilocystidia are similar to those of E. sericellum, which has, however, a tomentose to minutely squamulose pileus, that usually turns yellow ochre with age.

/Ritae subclade

The well-supported subclade /Ritae contains at least four species, one of them is Entoloma ritae, a well delimited species in subgen. Alboleptonia with pinkish brown basidiomata (Wölfel & Noordeloos 1997b), and the rather similar, pink-coloured E. pallidipes from North America (Noordeloos 1988). There are two more species in this clade, possibly undescribed, viz. Entoloma aff. ritae known from Norway and Germany, and Entoloma aff. cuboidoalbum from The Netherlands (Fig. 12, both as Entoloma sp.). For both taxa, however, the material is too limited to describe them formally.

/Olivaceotinctum clade

This clade partly coincides with Entoloma sect. Griseorubida, subsect. Parvisporigera sensu Noordeloos (1987). It accommodates species with small spores and less pronounced cheilocystidia as compared to subsect. Griseorubida. In Noordeloos (2004), this subsection comprised seven species. From five of these, holotypes could be sequenced, while the types of E. weholtii, and E. riofriense unfortunately failed. As a result, E. farinasprellum, and E. sordidolamellatum were found to belong to sect. Erophila, and the remaining three species (E. politoflavipes, E. moguntinum, E. olivaceotinctum) appeared to be conspecific. Since the name E. olivaceotinctum has priority, the remaining two names were added to the synonymy of that species. Considering the remarkable morphological variation, an amended description is given that covers the clade and the currently only recognized species (Fig. 2).

Entoloma olivaceotinctum Noordel., Persoonia 12(4): 461. 1985. MB 104246. Fig. 19.

Fig. 19.

Entoloma olivaceotinctum (A. TUR177404, isotype of E. olivaceotinctum; B. L0608339, holotype of E. olivaceotinctum; C. O-F-247975; D. Compiled from the isotypes of E. politoflavipes, holotypes of E. olivaceotinctum and E. moguntinum). A, C. Habit. B. Basidiospores. D. Cheilocystidia variability. Photos: A by J. Vauras; C by T.E. Brandrud. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia), 20 μm (pileipellis).

Synonyms: Entoloma politoflavipes Noordel. & Liiv, Persoonia 15(1): 29. 1992. MB 358182.

Entoloma moguntinum Noordel. & Prüfert, in Noordeloos, Entoloma s.l., Fungi Europaei vol. 5 (Saronno) 5a: 1111. 2004. MB 491782.

?Entoloma weholtii Noordel., Beih. Nova Hedwigia 91: 200. 1987. MB 133107.

Typus: Finland, Savonia Borealis, Kuopio, Puijo, Antikkala, 9 Aug. 1983, J. Vauras, 1552F (holotype L0608339, isotype TUR177404); ITS sequence, GenBank PX412050.

Description (amended here): Basidiomata collybioid. Pileus (5–)10–40 mm wide, campanulate or convex with slightly depressed to umbilicate centre and involute then deflexed margin, hygrophanous, when moist translucently striate at margin or up to centre, yellow brown, moderately dark brown, or grey brown sometimes with olivaceous green tinge, radially fibrillose at margin, rugulose to minutely squamulose at centre. Lamellae distant (L = 10–30, l = 3–7), broadly adnate often slightly emarginate or with small decurrent tooth, arcuate to segmentiform or ventricose, white or pale grey then pink with concolourous, entire edge. Stipe 10–50 × 1–3 mm, cylindrical, sometimes slightly broadened towards base, whitish to pale brown, yellow brown or grey brown sometimes with distinct olivaceous tinge at least when young, polished or substriate with innate fibrils (lens), rarely silvery striate. Context concolourous with surface in cortex, pallid in inner parts. Smell and taste indistinct. Basidiospores (200/16) (5.5–)6.0–9.0 × 5.5–7.5 µm, on average 7.0–8.5 × 6.2–6.8 µm, Q = 1.20–1.50, Qav = 1.35–1.42, 5–7-angled in side view. Basidia 20–30 × 8–12 μm, 4-spored, clamped. Lamella edge sterile or heterogeneous. Cheilocystidia 15–70 × 6–20 µm, very variable in shape from irregularly subcylindrical–subcoralloid to clavate or vesiculose, clamped. Pileipellis a cutis with transitions to a trichoderm, made up of strongly inflated, clavate to sphaeropedunculate, 12–25 µm wide elements; pigment brown to olivaceous–brown, intracellular. Stipitipellis a cutis of narrow, cylindrical, 3.0–12 μm wide hyphae; caulocystidia absent. Brilliant granules sparse in pileitrama. Clamp-connections abundant in hymenium, elsewhere rare.

Habitat and distribution: In small groups in xerophytic grasslands on calcareous soil or in semi-natural, grazed pastures, also found in forests on humus rich soil under Carpinus and Quercus on calcareous loam, and in mixed, often grazed forests, with Alnus incana, Betula, Salix, Picea, from July to October. Widespread in Europe.

Additional material examined: Estonia, Saaremaa, Viidu, 11 Aug. 1985, V. Liiv, Liiv 171 (L0054033, holotype of E. politoflavipes; ITS sequence, GenBank PX401858). Denmark, Sjælland, Fårevejle Kirkeby, Kårup Skov, Lerbjerg, semi-natural grassland, 31 Jul. 2011, R. Ejrnæs, DMS-159525. Germany, Rheinland-Pfalz, Mainz-Lerchenberg, Ober-Olmer Wald, 20 Jul. 2001, W. Prüfert (L0820376, holotype of E. moguntinum; ITS sequence, GenBank PX401857). Hungary, Veszprém, Bakony Mts, Eplény, 8 Sep. 2018, B. Dima, DB-2018-09-08-2 (ELTE). Norway, Møre og Romsdal, Rauma, Gjerde, semi-natural grassland, 1 Sep. 2000, J.B. Jordal (O-F-178061); Trøndelag, Sør-Trøndelag, Oppdal, Ørstad, by Egga, calcareous semi-natural grassland, 20 Aug. 2009, J.B. Jordal (O-F-291389); Akershus, Oppland, Lunner, Amundrud nordre, rather dry, calcareous lawn, 6 Aug. 2014, T.E. Brandrud, TEB 61-14 (O-F-247975); Innlandet, Oppland, Sør-Fron, Ommundgardshågån (Hundorp), dry calcareous semi-natural grassland, 8 Sep. 2005, J.B. Jordal, JBJ-3080 (O-F-158260). Russia, Tver Oblast, Zubtsov District, 2 km to SE from Mozgovo Village, right bank of the Derzha River, on soil in calcareous grassland, 11 Sep. 2015, O. Morozova, 46TV15 (LE F-311802, as E. moguntinum); ibid., 45TV15 (LE F-311803, as E. moguntinum ; Morozova et al. 2016); Pskov Oblast, Pechory District, vicinity of Stary Izborsk Village, near the Truvor hillfort, on soil in calcareous grassland, 20 Aug. 2011, O. Morozova, 4IZ11 (LE F-311836); Karachaevo-Cherkesia Republic, Teberda Nature Reserve, near Teberda town, on soil in grassland, 6 Aug. 2009, O. Morozova, 17TB09 (LE F-343749); Altai Republic, Altaiskiy Nature Reserve, cordon Chelyush, on soil in grassland near farm, 28 Aug. 2018, O. Morozova, 13AL18 (LE F-343762). The Netherlands, prov. Zuid Holland, Voornes Duin, 7 Aug. 2023, E. Vis (L0607501); prov. Limburg, Nijswiller Noord, 16 Oct. 2019, F. & R. Salzmann, PSLhg 00277 (L0607720).

Notes: Entoloma olivaceotinctum appears to be a very variable species. Despite the specific name, olivaceous tinges are not as often seen in this species as the name suggests, and the microscopy with regard to size and shape of the cheilocystidia is very variable. It resembles species of subgen. Cyanula, with which it often co-occurs in calcareous grassland hotspots, but is different because of the presence of clamp-connections. It is usually also easily distinguished from Cyanula species by the structure of the pileipellis. Now it takes a rather isolated position in the ITS tree outside subgen. Cyanula (Fig. 1). In addition to the listed additional material, we have seen many more sequenced collections of this species (e.g. 16 collections from Denmark), which does not seem to be rare in Europe. We examined and sequenced several collections labelled E. weholtii, with broad clavate to vesiculose cheilocystidia, and these appeared to be conspecific with E. olivaceotinctum. However, the holotype of E. weholtii failed so far in our attempts to have it sequenced. So, the synonymy is not yet confirmed with a barcode sequence of the type.

/Griseorubidum clade – sect. Griseorubida

Entoloma sect. Griseorubida (Romagn.) Noordel., Persoonia 11(2): 147. 1981. MB 860553.

Basionym: Rhodophyllus sect. Griseorubidi Romagn., Bull. Mens. Soc. Linn. Lyon 43: 320. 1974. MB 634402.

Type species: Entoloma griseorubidum Kühner ex Noordel.

This clade coincides with Entoloma sect. Griseorubida (Romagnesi 1974, Noordeloos 1987). The main morphological characters are the collybioid habit, usually with a distinctly umbilicate, fibrillose to minutely squamulose pileus; a polished stipe; large fusiform to lageniform cheilocystidia, sometimes in addition similarly shaped pleurocystidia, and presence of clamp-connections. Noordeloos (1987) distinguished two species, viz. E. griseorubidum, and E. indutoides, based on differences in colour and spore size. Noordeloos et al. (1995) concluded on the basis of some rich, additional collections that these differences did not stand and considered E. griseorubidum a synonym of E. indutoides. In the same paper, a new variety, E. indutoides var. pleurocystidiatum was introduced for a collection with distinct pleurocystidia. Noordeloos (1987) published E. insolitum as a new species in subgenus Paraleptonia, with an omphalinoid habit, and well differentiated cheilo- and pleurocystidia. The results of our molecular studies, however, show that we need to have a fresh look at species limits in this clade. Entoloma griseorubidum forms a distinct clade, and includes the holotypes of E. indutoides var. pleurocystidiatum, as well as that of E. insolitum. A sister-clade, differing by 7.5–8.5 % in the ITS, is described here as E. paraindutoides, based on one collection from Italy, and two from Estonia (UNITE). The holotype of E. indutoides, however, groups together with a few Norwegian collections as a distinct separate clade and must be considered a species in its own right. Despite the barcode gaps, the three species are morphologically hardly distinguishable. In the /Griseorubida clade (Fig. 20) we find, furthermore, the recently described E. ochraceodiscum, that can be distinguished by the colour of the basidiomata (Kaygusuz et al. 2024), and the extralimital E. contortisporum from the island of Réunion, with rather an aberrant spore shape (Noordeloos & Hausknecht 2007).

Fig. 20.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma sect. Griseorubida and sect. Atricoloria. ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma griseorubidum Kühner ex Noordel., Persoonia 12(3): 196. 1984, amend. MB 106088. Fig. 21.

Fig. 21.

Entoloma griseorubidum (A. L0607633; B. L0607632; C–E. Huijsman 10-Jul-1965, holotype). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E. Pileipellis. Photos: M. Dondl. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (basidiospores and cheilocystidia), 20 μm (pileipellis).

Synonyms: Entoloma insolitum Noordel., Beih. Nova Hedwigia 91: 348. 1987. MB 133092.

Entoloma indutoides var. pleurocystidiatum Noordel. et al., Öst. Z. Pilzk. 4: 127. 1995. MB 413016.

Misapplied name: Entoloma indutoides (P.D. Orton) Noordel., Persoonia 12(3): 198. 1984, sensu Noordel. et al., Öst. Z. Pilzk. 4: 126–127. 1995.

Typus: Switzerland, Neuchâtel, Marin, 10 Jul. 1965, H.S.C. Huijsman (holotype L, in poor condition, not sequenced). Germany, Bayern, Bad Endorf, Antwort, Antworter Berg, gregarious, on a moraine heap from the Würm glaciation, in a damp, herbaceous spot at the edge of a path, 24 Aug. 2013, M. Dondl (epitype L0607635, designated here, deposited at L, MBT 10028195); ITS sequence, GenBank PX412038.

Description (amended here): Basidiomata collybioid to omphalinoid. Pileus 15–30 mm, hemispherical to convex then expanding to applanate, with slightly depressed to umbilicate centre, with involute margin, slightly hygrophanous, not translucently striate, when moist very dark brown almost black to sepia, chocolate brown or dark grey brown, slightly pallescent on drying to brown, more or less coarsely radially fibrillose or tomentose, at centre sometimes breaking up in small squamules, opaque. Lamellae distant to somewhat crowded (L = 15–25, l = 1–5), very broad, up to 5 mm broad, thickish, adnate with indistinct decurrent tooth to distinctly decurrent, pale grey to grey brown with slight pink tinges, with an entire, slightly paler edge. Stipe 20–52 × 1.5–6 mm, cylindrical, equal, or with broadened base, young rather pale, almost white, then darkening to brown or grey brown, fibrillose, particularly in upper half or subglabrous; white pruinose to flocculose at apex, at base with white tomentum. Context white on drying, brown in cortex of pileus and stipe. Smell and taste not distinctive. Basidiospores (100/7) 10.5–14.0 × 7.0–10.5 μm, on average 11.5–12.5 × 8.5–9.0 µm, Q = 1.30–1.70, Qav = 1.40–1.45, irregularly 6–10-angled in sideview. Basidia 25–45 × 10–14 µm, 4-spored, clamped. Lamella edge heterogeneous. Cheilocystidia 40–145 × 5–17 µm, variable in shape from cylindrical, often capitate, to lageniform with a long, tapering neck, abundant to sparse, often in clusters or solitary among basidia. Pleurocystidia 25–130 × 5–20 × 3–7 µm, cylindrical, often capitate, to lageniform, more or less similar to cheilocystidia, abundant to sparse, easily collapsing and often hard to find in dried material, possible sometimes virtually absent. Pileipellis a cutis of radially arranged, cylindrical to inflated hyphae, up to 20 m wide, with cylindrical to inflated, terminal elements, 40–90 × 6–10 µm. Stipitipellis a cutis of cylindrical hyphae, 4–15 m wide with scattered or clustered cylindrical to lageniform caulocystidia, at apex only, 20–55(–80) × 5–20 µm. Pigment brown, intracellular in pileipellis and stipitipellis. Clamp-connections abundant.

Habitat and distribution: On soil in grasslands, preferring calcareous soil, including rich/calcareous moraines, often in montane to subalpine habitats, also among grasses at roadsides in mixed parkland. Apparently rare.

Additional material examined: Austria, Oberösterreich, Sankt Lorenz, Drachenwand Nord, 11 Sep. 1998, A. Hausknecht (WU-Myc 19603); Steiermark, Bad Gleichenberg, Kurpark 25 Jun. 1994, W. Klofac (WU12834, holotype of E. indutoides var. pleurocystidiatum; ITS sequence, GenBank PX412041). Germany, Bayern, Landkreis München, Baiersbrunn, western bank of the Isar, in alluvial forest on sandy fluvisol, 24 Jun. 2018, M. Dondl (L0607633); München, Fröttmaninger Heide, in a semi-natural grassland with Salix on calcareous soil, grazed by cattle, 27 Jun. 2009, M. Dondl (L0607632); ibid., 18 Aug. 2010, M. Dondl (L0607240). Switzerland, Canton of Vaud, Pont de Nant sur Bex, 8 Sep. 1984, Th.W. Kuyper, 2528, (L0054007, holotype of E. insolitum; ITS sequence, GenBank PX412043).

Notes: The holotype being in bad condition, unsuitable for molecular studies, made it necessary to designate an epitype with an ITS barcode. Morphologically, E. griseorubidum is very similar to E. indutoides (see below). Both occur almost exclusively in calcareous, dry grasslands, but E. griseorubidum seems to be more montane-subalpine, mainly (only?) in Central Europe.

Entoloma indutoides (P.D. Orton) Noordel., Persoonia 12(3): 198. 1984, amend. MB 106091. Fig. 22A–D.

Fig. 22.

A–D. Entoloma indutoides (A. LE F-254354; B. O-F-260876; C, D. Holotype). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E–G. Entoloma paraindutoides (AGMT-13670, holotype). E. Habit. F. Cheilocystidia. G. Basidiospores. Photos: A by O. Morozova; B by G. Gaarder; E by S. Toninelli. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia), 20 μm (pileipellis).

Basionym: Leptonia indutoides P.D. Orton, Trans. Brit. Mycol. Soc. 43(2): 295. 1960. MB 333200.

Typus: UK, England, Yorkshire, Ingleton, in limestone pasture, 28 Aug. 1958, P.D. Orton [holotype, K(M)108968]; ITS sequence, GenBank LN850608.

Description (amended here): Basidiomata omphalinoid, rather compact and firm. Pileus 15–30 mm wide, convex, then plano-convex, umbilicate or slightly depressed, with deflexed then straight margin, not distinctly hygrophanous or translucently striate, sepia brown to dark grey brown, almost black or sepia brown, often with olivaceous hue, or entirely dark olivaceous brown, entirely covered in very fine, glistening fibrillose-patches or minute squamules, becoming micaceous and streaked with darker fibrils upon drying. Lamellae somewhat thickened (L = 20–24, l = 1–3), and veined at the base, adnate-subdecurrent or emarginate, segmentiform to subventricose, pale yellow brown then brown pink, with pale coloured or white, entire or minutely flocculose-denticulate edge. Stipe 15–40 × 2–4 mm, equal or tapering downwards or thickened at the apex, sometimes slightly eccentric, solid then hollow, concolourous with pileus or paler dull brown to dirty yellowish brown, sometimes slightly tinged olive brown, entirely covered in fine fibrillose patches or subfibrillose, contrasting with the darker background. Context concolourous with the surface in the cortex, pale in inner parts. Smell indistinct, taste not noted. Basidiospores (120/7) 11.0–15.0 × 7.0–10.5 μm, on average 12.0–12.5 × 8.5–9.5 µm, Q = 1.25–1.70, Qav = 1.40–1.50, irregularly 6–8(–10)-angled in side view. Basidia 4-spored, 44–50 × 11–13 µm. Cheilocystidia 50–120 × 10–22 µm, scattered along edge, and sometimes also found on sides close to the edge and then often called pleurocystidia, lageniform or irregularly cylindrical to flexuous, 4–10 µm wide at the apex. Pileipellis a cutis of cylindrical, 4–22 µm wide hyphae, with brown intracellular pigment. Stipitipellis a cutis of cylindrical hyphae, 5–15 µm wide. Caulocystidia absent.

Habitat and distribution: In calcareous, dry, sometimes grazed grasslands, often in sites with many Entoloma subgen. Cyanula species. So far known from Norway, Russia, and the United Kingdom.

Additional material examined: Norway, Telemark, Bamble, Steinvika, in natural, dry grassland on limestone, 12 Aug. 2016, T.E. Brandrud & B. Dima, TEB 191-16 (O-F-254635); Telemark, Kragerø, Jomfruland, in semi-natural, grazed grassland on calcareous sand (shell-bed), Aug. 2011. T.E. Brandrud, TEB 55-11 (O-F-248386); Nordland, Bodø, Ausvika, calcareous meadow near the shore, 12 Aug. 2020, G. Gaarder & P. Alvereng, GG7826 (O-F-260876). Russia, Leningrad Oblast, Gatchina District, Pudost Village, on soil in calcareous grassland, 15 Jul. 2008, O. Morozova & E. Popov, LE F-254354; ibid., Paritsy Village, on soil in calcareous grassland, 4 Sep. 2023, O. Morozova & E. Popov, 2LO23 (LE F-344071).

Notes: Entoloma griseorubidum and E. indutoides are very similar morphologically, but differ slightly in colour, E. indutoides may be sometimes somewhat darker and with olivaceous tinges. Entoloma indutoides also seems on average more omphalinoid. Microscopically, the occurrence of pleurocystidia seems to be of minor taxonomic importance, as they may be present or absent in both species. The recently described E. ochraceodiscum differs from both E. griseorubidum, and E. indutoides by the combination of funnel-shaped basidiomata with deeply depressed, yellowish brown pilei, pale greyish to yellowish stipes with a dark yellow tinge, 5–8-angled basidiospores, and the presence of pleurocystidia and caulocystidia (Kaygusuz et al. 2024).

Entoloma paraindutoides Toninelli, Noordel. & Dima, sp. nov. MB 860387. Fig. 22E–G.

Etymology: παρά (para, Greek) – besides, along, referring to the close similarity to Entoloma indutoides.

Typus: Italy, Trentino, Castello-Molina di Fiemme (TN), Riserva Naturale Locale Brozin, on soil in open grassland, 29 Aug. 2014, S. Toninelli, ST77 (holotype, AGMT-13670); ITS sequence, GenBank PX412055.

Description: Pileus 20–30 mm wide, convex, umbilicate, with deflexed margin, not hygrophanous or translucently striate, sordid grey brown, sepia brown, more or less uniformly coloured or with slightly darker centre, innately fibrillose. Lamellae fairly distant (L = 36–52, l = 3–7), more or less segmentiform, adnate-subdecurrent, pallid then pink with entire, concolourous edge. Stipe 20–45 × 2–4 mm, cylindrical, equal or thickened at the apex, pale grey brown, subconcolourous with the pileus, when young entirely covered in fine fibrillose patches contrasting with the darker background. Basidiospores (20/1) 10.0–13.5 × 7.0–9.5 μm, on average 11.0–12.5 × 8.0–9.0 µm, Q = 1.20–1.60, Qav = 1.30–1.50, irregularly 6–8(–10)-angled in side view. Basidia 4-spored, clamped. Cheilocystidia 50–120 × 10–22 µm, scattered along edge, and sometimes also found on sides (“pleurocystidia”), lageniform or irregularly cylindrical to flexuous 4–10 µm wide at the apex. Pileipellis a cutis of cylindrical, 4–20 µm wide hyphae, with brown intracellular pigment. Stipitipellis an undifferentiated cutis of narrow, cylindrical hyphae. Caulocystidia absent. Clamp-connections present in hymenium.

Habitat and distribution: So far known from the type locality in calcareous subalpine grassland of N Italy, and two collections with sequences from Estonia (UNITE), one of them from the Saaremaa Island (from calcareous grassland, alvar).

Additional material examined: Estonia, Läane Makand, Läane Nigula, Rannaküla, Haapsalu Inn, 28 July. 2023, T. Ploompeu (TUF137259); Saaremaa, Saaremaakond, Lümanda val, Kihelkonna, Mäebe, 15 Aug. 2010, V. Liiv (TUF204343).

Notes: Entoloma paraindutoides is phylogenetically and morphologically close to E. griseorubidum and E. indutoides but is well-supported in the phylogenetic analysis having ITS sequences differing by 7.5–8.5 % from those of its closest sister E. griseorubidum. A good photograph of one of the Estonian collections can be found on the UNITE website (UDB015261). Because of the limited material that has been studied, assessment of variability of the individual species within sect. Griseorubida is not without problems. This could explain the inability to morphologically separate several barcode species despite their distinct phylogenetic position.

/Cornatum clade – Entoloma sect. Atricoloria

Entoloma sect. Atricoloria Dima, Noordel., O.V. Morozova & Reschke, sect. nov. MB 860448. Fig. 20.

Description: Basidiomata collybioid to omphalinoid with umbilicate to deeply umbilicate, dark coloured pileus, adnate to decurrent lamellae; stipe with fibrillose covering; lamella edge fertile or heterogeneous with subcylindrical to clavate cheilocystidia; clamp-connections present in all tissues.

Type species: Entoloma atricolor O.V. Morozova, Noordel., E.S. Popov & A.V. Alexandrova

Etymology: Named after the type species, Entoloma atricolor, and referring to the dark colour of its basidiomata.

Entoloma cornatum Fadnes, J.B. Jordal, Brandrud, Noordel. & Dima, sp. nov. MB 860388. Fig. 23.

Fig. 23.

Entoloma cornatum (A, C, D. O-F-261058, holotype; B. TEB 121-23). A, B. Habit. C. Basidiospores. D. Pileipellis. Photos: A by P. Fadnes & J.B. Jordal; B by T.E. Brandrud, Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia), 20 μm (pileipellis).

Etymology: cornu (Lat.) – small horn, referring to the trumpet-like musical instrument.

Typus: Norway, Vestland, Hordaland, Stord, Hovaneset, 4–5 m.a.s.l., semi-natural grassland, grazed by sheep, on shallow, calcareous soil near the sea, 28 Sep. 2021, P. Fadnes & J.B. Jordal, JB21-102 (holotype O-F-261058); ITS sequence, GenBank PX412031.

Description: Basidiomata collybioid to omphalinoid. Pileus 14–30 mm wide, weakly to deeply umbilicate, with involute, finally deflexed margin, not distinctly hygrophanous or translucently striate (or very weakly radially striate), medium to dark grey, sometimes greyish brown, but appearing paler because of the dense, fibrillose-aeriferous covering, greyish upon drying, with a dark grey brown “spot” at centre, surface radially fibrillose with silvery to dark fibrils, sometimes minutely squamulose, at centre sometimes weakly squamulose or granulose, shiny. Lamellae distant to moderately crowded (L = 20–27, l = 1–3), sometimes forked near the margin, arcuate-deeply decurrent, thickish, whitish, turning sordid pale grey pink with age; with entire, thick, concolourous edge, sometimes anastomosing basally. Stipe 20–40 × 2–3.5 mm, central or slightly eccentric, cylindrical, straight or slightly curved towards base, medium grey to greyish brown, entirely white felted-fibrillose. Context thin, concolourous with surface. Smell indistinct, taste not noted. Basidiospores (60/4) 8.4–11.2 × 5.9–8.2 μm, on average 9.6 × 7.0 µm, Q = 1.20–1.55(–1.70), Qav = 1.30–1.35, heterodiametrical with 6–8 angles in side view. Basidia 16–28 × 8–18 µm, narrowly clavate, 4-spored, clamp-connections absent. Lamella edge fertile. Cheilocystidia absent. Hymenophoral trama regular, made up of cylindrical elements, 60–110 × 5–9 µm. Pileipellis a cutis of narrow, cylindrical hyphae, 8–12 µm wide, with intracellular pigmentation; subpellis regular, made up of long hyphal elements, 6–25 µm wide. Stipitipellis a cutis of narrow, cylindrical hyphae. Caulocystidia absent. Clamp-connections not seen in any tissue.

Habitat and distribution: In groups in sheep-grazed, semi-natural grassland near the sea, on shallow soil influenced by calcareous, marine deposits (shell-beds). Autumn. Hitherto only three collections are known, two from places near the type locality, and one from another locality, all in coastal S Norway.

Additional material examined: Norway, Vestland, Hordaland, Stord, Hovaneset, semi-natural grassland grazed by sheep, 21 Aug. 2013, P. Fadnes, PF322 (O-F-245862); ibid., 8 Sep. 2014, P. Fadnes (O-F-75970); Telemark, Kragerø, Østre Gumøy, semi-natural sheep-grazed grassland, on rich (more or less calcareous) shallow, seasonally moist soil, 27 Jul. 2023, T.E. Brandrud, TEB 121-23 (O-F-297402).

Notes: Entoloma cornatum is macroscopically reminiscent of E. fridolfingense, but that species is stouter, has somewhat different colours (the pileus is more brownish), the lamellae have a sterile to heterogeneous edge and are never forked or venose, and it is phylogenetically very distant. The species may also resemble E. indutoides, but this is more fibrillose-opaque and is not so markedly omphalinoid. Entoloma cornatum groups together with E. atricolor from Vietnam (Morozova et al. 2016) and is more distantly related to European species, like E. violaceozonatum.

/Velenovskyi clade

This well-supported clade (Fig. 1) contains several OTU’s with a wide geographical distribution in Europe, North America, and Asia (China, Mascarenes). Morphologically, they are characterised by a more or less mycenoid habit, with conical to convex pileus, often with a truncate to subumbilicate apex, ascending, ventricose lamellae, and a slender, often more or less polished stipe. Microscopically, all exhibit voluminous, fusiform to lageniform cystidia along the lamella edge (cheilocystidia), and sometimes also on the sides in the proximity of the edge (pleurocystidia). As in sect. Griseorubida, the presence or absence of pleurocystidia appears to be not taxonomically informative. Basidiospores are usually large, but their sizes vary greatly, sometimes within one species. For that reason, it is hard to differentiate these species morphologically. Five clades are recognized as good species (Fig. 24), viz. the clades containing the holotype of respectively E. calaminare from Europe (Noordeloos 1984), and E. subelegans from the Mascarenes (Noordeloos & Hausknecht 2016). The latter has a basal position within the /Velenovskyi clade. The holotype of E. velenovskyi at PRC (as Leptonia conica), is preserved in ethanol, and for that reason unsuitable for DNA sequencing. An epitype has therefore been designated herein to fix the name E. velenovskyi with a representative specimen and ITS barcode. Entoloma cognatum is described here as new to science.

Fig. 24.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma clade /Velenovskyi. ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma calaminare Noordel., Persoonia 12(3): 198. 1984. MB 106081. Fig. 25.

Fig. 25.

Entoloma calaminare (A. ENT10080901; B. L0053486, holotype; C–F. L0608095). A, D. Habit. B, G. Basidiospores. C, F. Cheilocystidia. E. Pileipellis. Photos: A by J. Kleine; C by M.J.C. van der Vegte; D–G by G.M. Jansen. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores), 20 μm (cheilocystidia and pileipellis).

Typus: The Netherlands, prov. Limburg, Cottessen, riverbank of de Geul, in xerophytic grassland with a high content of zinc, 21 Sep. 1978, M.E. Noordeloos, MEN729 (holotype L0053486); ITS sequence, GenBank PX401860.

Description: Basidiomata collybioid. Pileus 15–20 mm wide, hemispherical to conico-convex, often truncate, with umbilicate centre or with small papilla, with deflexed or straight margin, not or weakly hygrophanous, when moist variable in colour from very pale grey or ochraceous brown to warm reddish brown, with darker brown centre and striae, translucently striate at margin up to 2/3 of radius, pallescent to pale brown or almost white on drying, radially fibrillose, when exposed to weathering reminiscent of a species of Inocybe, shiny. Lamellae moderately distant (L = 15–20, l = 1–3), adnate-emarginate, sometimes with decurrent tooth, triangular to segmentiform or subventricose, white to pale grey or brown then greyish pink, with entire or fimbriate, concolourous edge. Stipe 25–50 × 1–3 mm, cylindrical, sometimes tapering towards base, pale cream or brownish grey, often with distinct ochre tinge near base, glabrous, polished or with scattered fibrils under lens, at base white tomentose. Context concolourous with surface, very brittle. Smell and taste indistinct. Basidiospores (50/3) 9.0–14.0 × (6.7–)7.0–9.0 μm, on average 10.0–10.9 × 7.0–7.2 µm, Q = 1.20–1.60, Qav = 1.30–1.40, irregularly nodulose-angled with 5–7 angles in side view, with basal facet. Basidia 27–45 × 10.5–14 µm, 4-spored, clamped. Lamella edge heterogeneous. Cheilocystidia abundant, 27–100 × 5–20 µm, irregular in shape, cylindrical to clavate, lageniform or lecythiform, with rounded or capitate apex. Hymenophoral trama regular, made up of narrow, cylindrical hyphae 6–18 µm wide. Pileipellis a cutis with scattered trichodermal tufts of clavate, up to 15 µm wide terminal elements; pigment pale brown, intracellular. Stipitipellis a cutis of narrow, cylindrical hyphae. Caulocystidia absent. Brilliant granules present in pileitrama. Clamp-connections present in hymenium, rare in other tissues.

Habitat and distribution: Terrestrial in semi-natural grasslands or on bare soil in broad-leaved forests, also in mossy, marshy places, including riverbanks, from August to November. Rare, only known from a few localities in Germany and The Netherlands. The type is Dutch, from Limburg, collected by a river influenced by the Calamine zinc mine in Belgium.

Additional material examined: Germany, Sachsen, Leipzig, Nature Reserve Lehmlache Lauer, on bare loamy soil with broad-leaved trees, 9 Aug. 2010, J. Kleine, ENT10080901. The Netherlands, prov. Gelderland, Groesbeek, de Bruuk, in wet grassland, 2 Sep. 2018, M.J.C. van der Vegte & G.M. Jansen (L0608095).

Notes: For the present study only three collections were available, that form a rather well-supported clade in the tree. GenBank KC261490 groups together with the holotype, and a collection from The Netherlands (specimen L0608095) is very similar morphologically and differs mainly in the longer, lageniform cheilocystidia. We succeeded in getting only the ITS2-part for the holotype of E. calaminare with some ambiguities included. This part has only one unambiguous difference to the other two sequences. The other two sequences differ by 2.5 % from each other, which may well mean that they are two different species. Unfortunately, the majority of the differences are in the ITS1 region, so that we cannot be sure that the collection from Germany is really as close to the type as the tree indicates. Clearly, more collections and possibly even an epitype are needed to solve this, so treating them as one species is the most suitable and pragmatic solution for now. Another distinct clade, with five collections from Norway, is described as a species new to science below:

Entoloma cognatum J.B. Jordal, Noordel. & Dima, sp. nov. MB 860389. Fig. 26.

Fig. 26.

Entoloma cognatum (A, B. JB18-007; C–F. O-F-247460, holotype). A–D. Habit. E. Cheilocystidia. F. Basidiospores. Photos: J.B. Jordal. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia).

Etymology: cognatus (Lat.) – related, similar, i.e., similar to E. calaminare.

Typus: Norway, Trøndelag, Nord-Trøndelag, Namdalseid, Heggdalisetran, on soil in semi-natural pasture, 11 Sep. 2013, J.B. Jordal, H. Holien & H. Bratli (holotype O-F-247460); ITS sequence, GenBank PX412030.

Description: Basidiomata mycenoid. Pileus 6–12 mm broad, dark sepia brown, somewhat hygrophanous, deeply radially translucently striate, innately radially fibrillose, silky shiny when dry. Lamellae moderately distant (L = about 20, l = 3–5), narrowly adnate with small tooth, ventricose, pale, cream with paler, irregularly eroded edge. Stipe 30–40 × 1–2 mm, cylindrical, pale brown, much paler than pileus, polished or with scattered fibrils. Smell and taste indistinct. Basidiospores (50/4) 10.0–14.0 × 7.0–9.0 µm, on average 8.3 × 6.7 µm, Q = 1.05–1.40, Qav = 1.20–1.30, nodulose, 4–9-angular. Basidia 4-spored, clamped. Lamella edge heterogeneous. Cheilocystidia 55–95 × 10–25 × 2–4 µm, lageniform, often with a rather acute, narrow apex. Pileipellis a cutis of narrow, 2–7 µm wide hyphae; pigment brown, intracellular. Stipitipellis a cutis of narrow, cylindrical hyphae. Caulocystidia absent. Brilliant granules not observed. Clamp-connections present in all tissues.

Habitat and distribution: In small groups in semi-natural, calcareous grassland. So far only known from Norway (mainly from Central Norway).

Additional material examined: Norway, Innlandet, Oppland, Nord-Fron, Teige, semi-natural pasture, 20 Sep. 2004, B.H. Larsen, BHL66 (O-F-188870); Trøndelag, Sør-Trøndelag, Oppdal, Slettvoll, calcareous, semi-natural pasture, 24 Aug. 2009, J.B. Jordal (O-F-291327); Oppdal, Nerskogen below Håkersetra, semi-natural pasture with scattered birch trees, 3 Aug. 2009, J.B. Jordal (O-F-291315); Rennebu, Jøldalen, Bortstugusetra, semi-natural pasture, 23 Aug. 2018, J.B. Jordal, JB18-007 (O-F-256735).

Notes: Entoloma cognatum is morphologically hardly differentiated from E. calaminare and E. velenovskyi, but phylogenetically distant. Therefore, it is considered a good phylogenetic species.

Entoloma velenovskyi Noordel., Persoonia 10(2): 258. 1979. MB 313842. Fig. 27.

Fig. 27.

Entoloma velenovskyi (A. WU-Myc 13150, epitype; B. O-F-158201; C–F. GLM-F139799). A–C. Habit. D. Basidiospores. E. Pleurocystidia. F. Cheilocystidia. Photos: A by W. Klofac; B by J.B. Jordal; C by A. Karich. Drawings by A. Karich. Scale bars: 1 cm (habit), 10 μm (spores and cystidia).

Replaced synonym: Leptonia conica Velen. České Houby 3: 623. 1921. MB 486653, non Leptonia conica (Murrill) Sacc. & Trotter, Syll. Fung. 23: 214. 1925. MB 173049.

Typus: Czechia, Central Bohemia, Mnichovice near Praha, Jul. 1919, J. Velenovský (holotype PRC 9972). Austria, Niederösterreich, Rohrbach, Rohrbachgraben, Buchberg, in calcareous grassland, 15 Sep. 1994, A. Hausknecht & W. Klofac (epitype WU-Myc 13150, designated here, deposited at WU, MBT 10028196); ITS sequence, GenBank LN850612.

Description: Basidiomata mycenoid-collybioid. Pileus 10–30 mm wide, acutely conical, campanulate or conico-convex, then expanding to convex, usually with prominent papilla, but also with a truncate centre, with margin slightly involute then straight and crenulate, weakly to distinctly hygrophanous, when moist translucently striate up to half the radius, rarely up to centre, moderately to dark grey brown, slightly paler at margin, slightly to strongly pallescent on drying to grey brown or ochraceous grey, glabrous to innately radially fibrillose, often slightly scurfy at centre. Lamellae moderately distant (L = 20–30, l = 1–5), adnexed, emarginate, often with deccurrent tooth, or broadly adnate with decurrent tooth, arcuate to ventricose, fairly thick, white then pink with sordid grey or brown tinge, with concolourous, entire edge. Stipe 15–70 × 1–3 mm, cylindrical, straight or flexuose, pale grey brown or yellow brown, glabrous, polished, sometimes white tomentose at base. Context thin, membranaceous, concolourous with surface. Smell none, taste mild. Basidiospores (200/12) 10.0–14.0(–16.0) × 7.0–11.5 μm, on average 12.5 × 8.3 µm, Q = 1.30–1.70, Qav = 1.45–1.50, rather variable in size and shape per collection, irregularly heterodiametrical, 5–9-angled in side view. Basidia 20–35 × 5–9 µm, 4-spored, clamped. Lamella edge sterile or heterogeneous. Cheilocystidia 50–150 × 6–20 × 2–5 µm, fusiform or lageniform, always distinct and abundant. Pleurocystidia (40–)60–100 × (8.5–)12.5–18 µm, similar to cheilocystidia, abundant or sparse, sometimes lacking. Pileipellis a thin cutis of narrow, cylindrical, up to 12 µm wide hyphae. Pigment brown, intracellular in pileipellis and upper pileitrama. Stipitipellis a cutis of cylindrical, 5–14 µm wide hyphae. Caulocystidia absent. Clamp-connections abundant.

Habitat and distribution: In small groups, terrestrial in semi-natural grasslands, mainly in more or less calcareous soils. Northern and Central Europe.

Additional material examined: Germany, Sachsen, Jonsdorf, Auf der Heide, Parkrasen, 8 Sep. 2020, A. Karich & R. Ullrich, IHI-20Ent07, AK08092020 (GLM-F139800); Lückendorf, Kurparkwiese, in poor grassland, 12 Sep. 2019, A. Karich & R. Ullrich, IHI-19Ent04, AK12092019 (GLM-F139799). Norway, Møre og Romsdal, Tingvoll, Eikrem, Skarahaugen, semi-natural grassland, 11 Sep. 2021, G. Gaarder, GG7956; ibid., GG7957; Trøndelag, Sør-Trøndelag, Oppdal, Engan, in calcareous, semi-natural grassland, 22 Aug. 2005, J.B. Jordal, JBJ3129 (O-F-158201); Rennebu, Aunan, Lønshaugen, 16 Sep. 2021, J.B. Jordal & S. Vatne, JB21-74 (O-F-261049); Rogaland, Rennesøy, Brimse, calcareous pasture, 2 Oct. 2006, J.B. Jordal & J.I. Johnsen (O-F-361190); Vestland, Luster, Mørkridsdalen, Larsamoøy, semi-natural grassland, 23 Aug. 2022, G. Gaarder & A.H. Abaz, GG8131. Sweden, Jämtlands län, near Angsta, Storvålen, horse pasture, 27 Aug. 2018, K. Reschke, KaiR 1243 (B 70 0105512).

Notes: There is some molecular variation in E. velenovskyi as shown in the tree (Fig. 24), but so far, we regard this as intraspecific genetic variability and treat all the sequences as belonging to one variable species.

/Pouzarella clade – subgen. Pouzarella

Entoloma subgen. Pouzarella (Mazzer) Noordel., Persoonia 12(3): 196. 1984. MB 840563.

Basionym: Pouzarella Mazzer, Bibliotheca Mycol. 46: 69. 1976. MB 18357.

Type species: Entoloma nodosporum (G.F. Atk.) Noordel.

The /Pouzarella clade coincides with Entoloma subgen. Pouzarella, a well-supported and delimited clade within Entoloma (Fig. 1) characterised by a mycenoid (-inocyboid) habit, a non-hygrophanous pileus with metallic-shining, fibrillose-hairy or subsquamulose surface, encrusting pigments in all tissues and the absence of clamp-connections. Sometimes they look very similar to tiny Inocybe species. Most species are rarely recorded but considering their small brownish basidiomata and their preference for shady, damp places in forest undergrowth, they are most likely overlooked. Pouzarella species occur worldwide (Fig. 28), which is reflected in a number of publications. Detailed monographic studies in Europe (Noordeloos 1979), North America (Mazzer 1979) and SE Asia (Horak 1980) already showed a remarkable species diversity. Regional studies confirmed this diversity (He et al. 2018, 2018, China; Baroni et al. 2008, Dominican Republic and Jamaica; Baroni et al. 2012, Argentina; Raj & Manimohan 2017, India; Karstedt et al. 2007, Brazil; Largent et al. 2011b, Australia). Despite the rather limited material we had at hand, it appeared from our phylogenetic studies that the number of well delimited species in Europe is higher than known so far, and new species needed to be described, and neotypes to be designated.

Fig. 28.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma subgen. Pouzarella (= /Pouzarella clade). ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

/Versatilis subclade

This moderately supported subclade (ML 78 %) coincides with Entoloma sect. Versatilia containing its type species E. versatile. The frequent E. araneosum and the less common E. canosericeum also belong to this clade, as well as several unnamed lineages and a few that we describe as new to science.

Entoloma araneosum (Quél.) M.M. Moser, Kl. Krypt.-Fl. (Stuttgart) 2b/2: 208. 1978. MB 313665.

Basionym: Nolanea araneosa Quél., Bull. Soc. Bot. France 23: 327. 1877.

Synonym: Entoloma araneosum f. robustum Noordel., Entoloma s.l., Fungi Europaei vol. 5 (Saronno) 5a: 971. 2004. MB 492423.

Typus: Quélet (1877), Bull. Soc. bot. Fr. 23: pl II, fig. 3. (lectotype, designated here, MBT 10028206). Belgium, prov. Namur, Viroinval, Oignies-en-Thiérache, in rich deciduous forest on calcareous soil, 22 Sep. 2003, M.E. Noordeloos, MEN200314 (epitype L0607183, designated here, deposited at L, MBT 10028207); ITS sequence, GenBank KC710056 (Morozova et al. 2014a), LSU sequence, GenBank GQ289153, mtSSU sequence, GenBank GQ289293, RPB2 sequence, GenBank GQ289225 (Co-David et al. 2009).

Additional material examined: Finland, Satakunta, Sastamala, Mouhijaervi, Salmi, Saviannokka, 18 Sep. 2011, L. Kosonen, FIPUT624-14 (TUR194139). Germany, Frankfurt am Main, Stadtwald, Jakobiweiher, in mixed deciduous forest on rich soil, wayside, on soil between leaf litter, 23 Oct. 2023, K. Reschke, KaiR1764 (B); Hessen, near Steinau an der Straße, Ulmbach, Naturreservat Weiherskopf, Fagus forest, 16 Oct. 2016, H. Böhning, C. Manz & A. Gminder, aCM02 (B); Sachsen, Lückendorf, Kurwiese, in calcareous grassland, 5 Nov. 2021, A. Karich, IHI-21Ent07 (GLM-F139004). Norway, Akershus, Bærum, Ostøya, calcareous mixed forest, 11 Sep. 2009, J. Markussen, T.E. Brandrud & E. Bendiksen, EB 202/06 (O-F-253938); Buskerud, Drammen, Strøtvet, by Boktrykker Köbkes bridge, edge of path in forest with Acer, Fraxinus, Sorbus, Picea, 22 Aug. 2014, G. Gulden, GG 4/14 (O-F-302288); Østfold, Moss, Reiertangen, wooded pasture with Quercus and Salix caprea, 8 Oct. 2012, R. Braathen & E.W. Hanssen (O-F-301579); Telemark, Kragerø, Kammerfossåsen, rich forest with Tilia, Populus and Fraxinus on amphibolite bedrock, 13 Jul. 2016, T.E. Brandrud, TEB 37a-16 (O-F-304846); Telemark, Bamble, Høgenheitunnelen V, calcareous Tilia forest, 20 Jul. 2016, T.E. Brandrud, TEB 66-16 (O-F-304862); ibid., Bunestoppen, calcareous broad-leaved forest with Corylus, Fraxinus, Quercus, Alnus incana, Betula and Equisetum hyemale, 2 Oct. 2022, B. Rian, M.S. Olsen, E41 (O-F-204238); Oslo, Oslo, Vollebekk, Sep. 2022, E. Bendiksen, EB 287/22 (O). Russia, Moscow Oblast, Odintsovsky District, Zvenigorod Biological Station of Moscow State University, on soil in mixed forest, 12 Aug. 2013, E. Voronina (LE F-254043); Ulyanovsk Oblast, on chalk soil in Tilia forest, 9 Aug. 1990, A.I. Ivanov (LE F-18948, as E. fulvostrigosum); Samara Oblast, Zhigulevsky Nature Reserve, vicinities of Bakhilova Polyana Village, Yagodnoye Pole, Tilia cordata-Acer platanoides forest, 5 Jul. 2005, E. Malysheva (LE F-234321); St Petersburg, Peter the Great Botanical Garden, on soil under Tilia cordata and Acer platanoides, 22 Sep. 2006, O. Morozova, Mycotheca Petropolitana, № 60 (LE F-262196); Pskov Oblast, Bezhanitsy District, Tzevlo Village, on soil in remnant of manor park with old-growth Tilia, 7 Sep. 2019, L. Kalinina (LE F-330284); Pskov Oblast, Pushkinogorsky District, between Bugrovo and Mikhailovskoye villages, on soil on roadside in a mixed forest, 11 Sep. 2018, O. Morozova, 3PG18 (LE F-315954); Karachay-Cherkess Republic, Teberda State Biosphere Reserve, Arkhyz site, vicinity of the Bukovo Village, on soil in Fagus orientalis-Carpinus betulus forest, 22 Aug. 2009, O. Morozova, 228TB09 (LE F-343753). Sweden, Medelpad, Borgsjö, Granboda, 31 Aug. 1993, M.E. Noordeloos, MEN 93131 (L, holotype of E. araneosum f. robustum); Uppland, Uppsala, Kronåsen, under Sambucus racemosa, 12 Sep. 1980, S. Ryman, 5877 (UPS F-624525).

Notes: There is no original herbarium material of this species, but a description and plate are available. The latter is designated as lectotype (above). An epitype is designated to support the current concept with an ITS barcode. A full description and illustrations will be given in the forthcoming monograph (see introduction).

Entoloma canosericeum (J.E. Lange) Noordel., Nordic J. Bot. 2(2): 157. 1982. MB 110637. Fig. 29.

Fig. 29.

Entoloma canosericeum (A. L0607728; B–D. L0607316). A, B. Habit. C. Basidiospores. D. Cheilocystidia. Photos: A by T. Glaser; B by G. Wölfel. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores), 20 μm (cheilocystidia).

Basionym: Rhodophyllus canosericeus J.E. Lange, Fl. Agaric. Danic. 5(Taxon. Consp.): Vlll, 98. 1940. MB 374415.

Typus: Denmark, Fyn, Kværndrup, on damp soil in old growth deciduous woodland, 14 Sep. 1938, J. Lange (holotype C-F-67095); ITS sequence, GenBank PX440385.

Description (amended here): Basidiomata mycenoid. Pileus 10–25 mm wide, conical, expanding with age to convex with broad umbo, slightly hygrophanous, deeply translucently striate when moist, fairly dark grey brown, sometimes with olivaceous hue, pallescent on drying, but later often turning blackish when very old, radially fibrillose to almost smooth, but in dry state somewhat felted-fibrillose. Lamellae moderately distant [L = 20–36, l = 1–3(–5)], adnate to almost free, ventricose, pale grey to dark grey, finally tinged pink, turning blackish when old, with an entire, concolourous edge. Stipe 20–60 × 1–3 mm, cylindrical, apex brown grey, downward grey to dark grey or almost black, over the whole length covered with silvery fibrils. Context thin, concolourous with surface. Smell indistinct, taste not noted. Basidiospores (110/5) 9.0–12.0 × 6.5–8.0(–8.5) μm, on average 10.4–11.0 × 7.2–7.6 μm, Q = 1.20–1.40, Qav = 1.25–1.30, 5–6-angled in side view with rounded angles. Basidia 30–60 × 10.5–18 μm, 4-spored, necrobasidia frequent. Cheilocystidia 35–70(–80) × 10.5–18 × 2–4 μm, slender to broadly lageniform, often with long, protruding and slender neck, numerous. Hymenophoral trama regular, made up of cylindrical cells, 270–400 × 25–57 μm, often with minutely encrusted walls. Pileipellis a simple cutis of narrow, cylindrical, 4–11 μm wide hyphae, with minutely encrusted walls. Stipitipellis cutis of cylindrical hyphae 5–12 μm wide, with encrusted walls, and pale brown intracellular pigment. Caulocystidia absent. Clamp-connections absent (see notes).

Habitat and distribution: In damp places in broad-leaved forest on black soil. Known from Denmark, Germany and the United Kingdom.

Additional material examined: Germany, Bayern, Chiemsee, mixed broad-leaved forest on moist soil, 5 May 2019, T. Glaser (L0607728); Nordrhein-Westfalen, Sauerland, Rosengartenweg bei Geseke, in deciduous woodland, 1 Jun. 2013., G. Wölfel, E02/3 (L0607316); Nordrhein-Westfalen, Witten, Hohenstein, 30 Sep. 2020, T. Hülsewig, ACN51 (B 70 0105498). UK, England, Durham, Peterlee, mixed woodland,18 Sep. 1970, C. Bas (L0607235).

Notes: Noordeloos (1982) published a redescription of Lange’s species, based on a study of the holotype. A second collection made by E. Horak, of which only line-drawings and notes were available, was considered to be identical with the type. However, the material of Horak had abundant clamp-connections, in contrast to the holotype. Horak’s collection has not been available for sequencing, unfortunately. Since neither the holotype nor the additional collections have clamp-connections, and the fact that the ITS sequences perfectly fit the subgen. Pouzarella, which is characterised by the lack of clamp-connections, it is now doubtful whether this second collection cited in Noordeloos (1982) really belongs to the same species. Entoloma canosericeum differs from the rest of the members of the /Araneosum subclade particularly in the deeply translucently striate, fibrillose pileus, and smaller spores with a rounded 5–6 angular outline, and a less differentiated pileipellis of cylindrical hyphae.

Entoloma chloridicolor Reschke, O.V. Morozova, Ukhanova & Noordel., sp. nov. MB 860422. Fig. 30.

Fig. 30.

Entoloma chloridicolor (A. B 70 0105521; B, C, I. B 70 0105519, holotype; D–H. LE F-0312000). A, B, G. Habit. C, D. Basidiospores. E. Basidium. F. Cheilocystidia. H. Pileal surface. I. Pileipellis. Photos: A–C, I by K. Reschke; G, H by I. Ukhanova. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores, cheilo- and caulocystidia), 20 μm (pileipellis).

Etymology: Referring to the bird Chloris chloris, which has similar greenish and brownish grey colours.

Typus: Germany, Hessen, Wingertsberg, Bockenau, on soil between leaf litter at the edge of a calcareous grassland, 9 Nov. 2019, K. Reschke, KaiR1454 (holotype B 70 0105519); ITS sequence, GenBank PX412029.

Description: Basidiomata mycenoid. Pileus 20–50 mm wide, conical, expanding to conico-convex, slightly hygrophanous, not translucently striate or at margin only, variable in colour from dark brown to greyish brown to greenish-olivaceous, slightly pallescent from centre upon drying, minutely to rather pronouncedly silky fibrillose with micaceous sheen. Lamellae (L = 24–36, l = 3–7), distant, adnate-emarginate, ventricose, up to 10 mm broad, brown to greyish brown with pink tinge, with paler, fimbriate, slightly glistening edge. Stipe 35–85 × 1–6 mm, cylindrical, pale brown to pale grey brown, appearing paler by the dense whitish fibrillose covering, shiny. Context in pileus olivaceous brown to brown in pileus and stipe. Smell indistinct. Taste somewhat farinaceous. Basidiospores (60/4) 9.5–12.0(–13.5) × 6.5–8.0 μm, on average 10.6–11 × 7.0–7.5 μm, Q= 1.35–1.70(–1.90), Qav = 1.40–1.50, 5–8 angular in side view. Basidia 36–46 × 9.5–11.5 μm, 4-spored, clavate, frequently with brown necropigment, clampless. Lamella edge heterogeneous with numerous lageniform to clavate-mucronate cheilocystidia, 65–150 × 15–31 × 3–5 µm. Pleurocystidia scattered, similar to cheilocystidia. Hymenophoral trama two-layered, with subcellular subhymenium with minutely encrusted walls, mediostratum regular, made up of cylindrical to subfusiform, 7–20 µm wide elements with membranal, and minutely encrusted walls. Pileipellis a loose cutis with transitions to a trichoderm of cylindrical hyphae with fusiform to subclavate terminal elements, 180–450 × 6–12 µm, gradually passing into pileitrama, subpellis not distinctly differentiated. Pileitrama regular, made up of cylindrical to inflated elements, up to 280 × 8–31 µm. Pigment in pileipellis mainly intracellular, diffuse and granular, in addition encrusted in pileipellis, hymenophoral, pilei- and stipititrama. Stipitipellis a cutis of cylindrical, 5–13 μm wide hyphae with brown encrusted walls, and light yellow brown, intracellular pigment. Caulocystidia absent, but outer stipitipellis hyphae with abundant cylindrical to slightly clavate, sometimes somewhat capitate outgrowths, up to 45 × 7.5 µm, mainly without septa, so continuous with stipitipellis hyphae, not encrusted. Clamp-connections absent.

Habitat and distribution: Terrestrial in grasslands, in litter in broad-leaved forest (Quercus, Fagus) and mixed forest (Pinus, Acer), on calcareous soils. Known from a few localities in Germany and Russia.

Additional material examined: Germany, Hessen, Wingertsberg, Bockenau, in calcareous grassland, 9 Nov. 2019, G. Wölfel (L0607662); Baden-Württemberg, Schwäbische Alp, Schelklingen, Justingen, Schachenheide, on soil in calcareous grassland, 3 Oct. 2023, S. Adamčík, KaiR1506, (as E. canosericeum; B 70 0105521). Russia, Stavropol Krai, Grachevsky District, near Krasnoye Village, on calcareous soil in Pinus sylvestris and Acer sp. planting, 26 Oct. 2011, I. Ukhanova (LE F-312000).

Notes: Entoloma chloridicolor is phylogenetically distinguishable from both E. versatile, and E. olivaceovirens. The holotype had a brown grey pileus, but additional material from Russia shows distinct green colours, like in E. versatile. So, they represent barcode species that cannot always be distinguished morphologically. Entoloma canosericeum differs among other features by having smaller basidiospores.

Entoloma olivaceovirens J.B. Jordal, Noordel. & Dima, sp. nov. MB 860423. Fig. 31.

Fig. 31.

Entoloma olivaceovirens (A. O-F-256802, holotype; B–D. IHI-13Ent01). A, B, D. Habit. C, E. Basidiospores. F. Cheilocystidia. Photos: A by P.R. Tingve; B–D by A. Karich. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Etymology: olivaceus (Lat.) – olivaceous, and virens (Lat.) – being green, referring to the colours of the basidiomata.

Typus: Norway, Møre & Romsdal, Ålesund, Fylling, on soil in Corylus forest, 25 Sep. 2019, P.R. Tingve, JBJ19-073 (holotype O-F-256802); ITS sequence, GenBank PX412051.

Description: Basidiomata inocyboid. Pileus 20–30 mm wide, conical to conico-convex with straight margin, not hygrophanous or translucently striate, olivaceous yellow, dark greyish with green shine of dark olivaceous, sometimes with paler, olivaceous yellow margin, entirely and coarsely radially fibrillose, reminiscent of an Inocybe. Lamellae moderately distant to fairly crowded [L = 36–50, l = 1–3(–5)], ascending, narrowly adnate, almost free, ventricose, dark grey, with pinkish tinge when mature, with slightly irregular, concolourous edge. Stipe 30–40 × 1–3, cylindrical, dark grey with green tinge, strongly silvery-fibrillose striate lengthwise, base with greyish mycelial tomentum. Context thin, concolourous with surface. Smell indistinct, taste not noted. Basidiospores (100/5) 7.5–11.0 × 6.5–8.0(–8.5) μm, on average 9.0–10 × 7.0–7.5 μm, Q = 1.20–1.60, Qav = 1.35–1.40, rather regularly 5–7-angled in side view with pronounced angles. Basidia 45–60 × 7–15 μm, 4-spored, clamped, necrobasidia frequent. Lamella edge almost sterile. Cheilocystidia prominent, 60–120 × 9–25 μm, fusiform to lageniform, thin-walled. Pleurocystidia present close to edge, similar to cheilocystidia. Hymenophoral trama with distinct hymenopodium, two-layered, regular, made up of cylindrical, 4–12 μm wide hyphae, with subcellular subhymenium with minutely encrusted walls, mediostratum regular, comprising cylindrical, 20–30 µm wide elements with membranal, sometimes minutely encrusted walls. Pileipellis a cutis with transitions to a trichoderm of fusiform to subclavate terminal elements, 90–170(–200) × 12–21 µm. Pileitrama regular, of cylindrical to inflated elements, up to 280 × 8–31 µm. Pigment membranal to finely encrusting in the pileipellis and pileitrama, in addition granular-intracellular in pileipellis. Clamp-connections absent.

Habitat and distribution: In semi-natural grassland, also found on bare soil in mixed broad-leaved forest with Fagus on calcareous loam. Known from a few places in Norway and Germany.

Additional material examined: Germany, Niedersachsen, Landkreis Holzminden, south of Holzminden, among leaf litter at a moist edge of the creek Holzminde, with Corylus, Acer, Fagus, Alnus, 5 Nov. 2023, R. Dost & F. Hampe, ACN63 (B 70 0105499); Nordrhein-Westfalen, Teutoburgerwald, Bad Meinsberg, among leaf litter in deciduous forest, 25 Aug. 1965, C. Bas, 4567 (L0607662); Sachsen, Oybin, Hausgrund, humose wet soil near calcareous spring, 5 Jul. 2017, A. Karich, IHI-13Ent01 (GLM-F139001). Norway, Møre & Romsdal, Ålesund, Litj-Kalvøya, Plassen, 5 m.a.s.l., 25 Sep. 1999, D. Holtan & J.B. Jordal (O-F-240927).

Notes: Entoloma olivaceovirens is a striking and beautiful species with its deep olivaceous grey colours, more intense than in the closely related E. versatile. In addition, the surface of the pileus is strongly fibrillose, reminiscent of an Inocybe species.

Entoloma peraraneosum G.M. Jansen, Noordel., Finy & Dima, sp. nov. MB 860424. Fig. 32.

Fig. 32.

Entoloma peraraneosum (L4343834, holotype). A, B. Habit. C. Basidiospores. D. Pileipellis. E. Lamella edge with cheilocystidia. Photos: G.M. Jansen. Scale bars: 1 cm (habit), 10 μm (spores), 20 μm (pileipellis and hymenial cystidia).

Etymology: περ (Greek) – besides, along, referring to the close similarity with E. araneosum.

Typus: The Netherlands, prov. Utrecht, Breukelen, Nijenrode, in rich deciduous parkland on calcareous clay, 17 Oct. 2015, G.M. Jansen, C15-2707 (holotype L4343834); ITS sequence, GenBank PX412056.

Description: Basidiomata inocyboid. Pileus 10–20 mm wide, conico-convex, with straight margin, not hygrophanous or translucently striate, greyish brown, strongly radially fibrillose with paler, loose fibrils, sometimes appearing virgate. Lamellae distant (L = 20–26, l = 1–3), adnate-emarginate, ventricose, brown with slightly paler edge. Stipe 50–60 × 1–2 mm, cylindrical, slightly broadened at base, brown like the pileus, darker towards the base, minutely hairy with slightly paler fibrils on the entire length, with strigose hairs at base. Context thin, concolourous with surface. Smell and taste farinaceous. Basidiospores (60/4) 10.5–15.0 × 7.0–9.0 μm, on average 11.5–13.5 × 7.7–8.5 μm, Q = 1.35–1.80, Qav = 1.60–1.70, 5–7-angled with rather pronounced angles. Basidia 4-spored, clampless. Lamella edge sterile. Cheilocystidia 70–115 × 20–40 × 2–5 μm, lageniform with long, tapering neck. Pleurocystidia sparse, similar to cheilocystidia. Pileipellis a cutis with transitions to a trichoderm, hyphae 4–9 μm wide, overlaying a darker layer of encrusted hyphae. Intracellular pigment not observed. Stipitipellis a cutis with transition to a trichoderm of narrow hyphal elements, with brown incrustations. Clamp-connections absent.

Habitat and distribution: Terrestrial on heavy clay soil in broad-leaved woodland and parkland. Known from three localities in The Netherlands, and one in Hungary, and one in Russia (Caucasus).

Additional material examined: Hungary, Vértes, Oroszlány, Gerencsérvár, in mixed deciduous forest, 30 Sep. 2023, P. Finy, FP-2023-09-30-1 (ELTE). Russia, Adygea Republic, Western Caucasus, Maykop District, vicinities of the Nikel Settlement, valley of the Syuk stream, overgrown sandbank, on soil in thickets of Alnus, 11 Sep. 2010, A.A. Kiyashko (LE F-269132). The Netherlands, prov. Zuid-Holland, Ridderkerk, Huijs ten Donk, deciduous parkland on heavy, calcareous clay, 12 Nov. 1977, T.W. Kuyper (L4400415); prov. Utrecht, Breukelen, Nijenrode, deciduous parkland on heavy, calcareous clay, 4 Nov. 1987, G. Immerzeel (L4400416); prov. Limburg, Valkenburg, Schaelrbergerbos, deciduous forest on calcareous loam, 20 Oct. 1991, E. Arnolds & P.J. Keizer (L4400418).

Notes: Entoloma peraraneosum is morphologically very similar to E. araneosum, however, it might be somewhat slenderer, and its ITS sequence differs by 2 % (11–12 substitution and indel positions) from that of typical E. araneosum.

Entoloma versatile (Gillet) M.M. Moser, Kl. Krypt.-Fl. (Stuttgart) 2b/2: 209. 1978. MB 313845.

Basionym: Nolanea versatilis Gillet, Hyménomycètes (Alençon): 414. 1876. MB 178182.

Replaced synonym: Agaricus versatilis Fr., Monogr. Hymenomyc. Suec. (Upsaliae) 2(2): 297. 1863. MB 487577, nom. illegit., non Agaricus versatilis Bertero & Mont., in Montagne, Annls Sci. Nat., Bot., sér. 2 8: 368. 1837. MB 102621.

Characteristics: Basidiocarps mycenoid. Pileus 15–30 mm broad, conical or campanulate then conico-convex, usually with small papilla, weakly hygrophanous, when moist not translucently striate or at margin only, usually rather dull-coloured olivaceous brown to olivaceous grey, occasionally more yellowish green, slightly paler when dry, glabrous or with innate fibrillose covering, sometimes minutely squamulose at centre, shining. Lamellae, distant, narrowly adnate to deeply emarginate, ventricose, grey then grey brown, finally with pink tinge, with floccose, concolourous edge. Stipe 25–50 × 2–3 mm, cylindrical, sometimes slightly broadened at base, pallid at apex, downwards grey to dark grey with distinct olivaceous tinge, at base often with reddish tinges, entirely striate to floccose with silvery fibrils, base strigose with white or reddish radiating hairs. Context thin, dark brown. Smell none or somewhat acidulous-spermatical. Taste not recorded. Terrestrial in humus of mixed or deciduous forest, along road-sides etc., preferably on rich, humus-rich soils. Basidiospores (9.0–)9.5–11.5(–12.5) × 7.0–8.0(–9.0) µm, Q = 1.20–1.50, Qav = 1.30–1.40, heterodiametrical, 5–8-angled in side-view. Basidia 4-spored, clampless. Lamella edge heterogeneous. Cheilocystidia (40–)60–110 × 10–25 µm, narrowly to broadly lageniform with broad basal part and long, tapering neck with thin, colourless walls, numerous, but always mixed with basidia. Pileipellis a transition between a cutis and a trichoderm, made up of radially arranged, cylindrical to inflated hyphae with up to 20 µm wide terminal elements. Pigment pale olivaceous-brown, intracellular in pileipellis, in addition also minutely encrusting the hyphae of lower pileipellis and upper pileitrama. Clamp-connections absent.

Typus: Holotype not existing. Sweden, Uppland, Uppsala, Kronåsen terrestrial in forest under Sambucus, in company with Entoloma araneosum and Melanophyllum echinatum, 15 Sep. 1980, S. Ryman, 5876 (neotype UPS F-121725, designated here, deposited at UPS, MBT 10028205); ITS sequence, GenBank PX412071.

Notes: Entoloma versatile is one of the Pouzarella species with greenish-olivaceous tinges, which usually are rather pronounced, sometimes more yellow green when perfectly fresh. Entoloma chloridicolor tends to become more brown with age, and E. olivaceovirens is distinctly deeper green to almost blue green. There is no original material of this species which was first (illegitimately) described by Fries. A neotype from the Uppsala area is designated here to support the current concept with an ITS barcode. A full description will be given in the forthcoming monograph.

/Strigosissmum subclade

This well-supported (ML 100 %) subclade (Fig. 28) contains two European species, viz. E. strigosissimum, and the here newly described E. brunneostrigosum (see below), as well as three other species from China among which only E. rubropilosum has been described.

Entoloma brunneostrigosum Enzlin, Noordel. & Dima, sp. nov. MB 860538. Fig. 33A, C–F.

Fig. 33.

A, C–F. Entoloma brunneostrigosum (L0607838, holotype). B. Entoloma pulvereum (Lectotype). A, B. Habit. C. Pileipellis details. D. Basidiospores. E. Setae on stipe. F. Cheilocystidia. Photos: R. Enzlin. Scale bars: 1 cm (habit), 10 μm (microstructures).

Etymology: brunneus (Lat.) – brown; strigosus (Lat.) – hairy, referring to the brown hairs on pileus and stipe.

Typus: The Netherlands, prov. Groningen, Island of Rottumerplaat, behind the shelter, 4 Nov. 2019, R. Enzlin, E24-081 (holotype L0607838); ITS sequence, GenBank PX412027.

Description: Basidiomata mycenoid. Pileus 8–25 mm wide, 4–6 mm high, broadly conical then semiglobose, later plano-convex to applanate with slightly depressed centre with low umbo, with involute then straight margin, dark grey brown to brown at centre, not hygrophanous, not translucently striate, surface coarsely fibrous with uplifted squamules to squarrose. Lamellae moderately distant (L = 20–30, l = 1–3), subventricose to segmentiform, narrowly adnate, incarnate grey to dark grey brown with pink tinge, with slightly paler edge. Stipe 30–45 × 1–2 mm, cylindrical, base sometimes enlarged, grey brown, upper part fibrillose, hardly hairy, lower part with patent reddish hairs, basal mycelium of stiff, reddish hairs. Context thin, brown. Smell and taste indistinct. Basidiospores (20/1) 14.5–17.5 × 7.5–10 μm, on average 15.5 × 9.0 μm, Q = 1.50–2.00, Qav = 1.79, nodulose-angular. Basidia 4-spored. Cheilocystidia 40–70 × 5–18 μm, cylindrical, lageniform or slender clavate. Pileipellis a cutis with transitions to a trichoderm of 7.5–15 μm wide hyphae with thick, coarsely encrusted walls. Stipitipellis a cutis of cylindrical, strongly encrusted hyphae, at base with very long, thick-walled setae with reddish walls and content. Clamp-connections absent.

Habitat and distribution: In coarse litter under Ligustrum bush on sandy, calcareous soil. So far only known from The Netherlands.

Notes: At first, we considered this collection to be E. pulvereum (Fig. 33B) in the sense of Orton and Noordeloos (Noordeloos 1979), but there are discrepancies, in particular in the size of the spores [10.2–12.5(–13.0) × 7.0–8.1(–8.7) μm, Q= 1.30–1.40–1.60], and lack of strigose hairs at the stipe base in E. pulvereum. It should be re-collected. Entoloma strigosissimum is similar but has long setae on the surface of the pileus, which are lacking in our species.

Entoloma strigosissimum (Rea) Noordel., Persoonia 10(2): 211. 1979. MB 313822.

Basionym: Nolanea strigosissima Rea, Trans. Brit. Mycol. Soc. 6(4): 325. 1920. MB 279003.

Typus: UK, England, Surrey, Weybridge, St. George’s College, on rotten wood in pine forest, 9 Oct. 1919, Ph. J. Alexander (holotype in K, lost); Rea (1920), Trans. Br. Mycol. Soc. 6: 325, pl. VII. (lectotype, designated here, MBT 10028209). The Netherlands, prov. Zuid Holland, Isl. Voorne, Parnassia Valley, 28 Jun. 1972, C. Bas, 5840 (epitype L4402841, designated here, deposited at L, MBT 10028210); ITS sequence, GenBank PX440389.

Notes: Noordeloos (1979) studied the type collection from Kew and depicted some of the microscopical details from this collection. However, a subsequent search for original material in the Fungarium of Kew was not successful, so we assume the type got lost. For that reason, the very informative type-plate of Rea is chosen here as lectotype. In addition, collection L4402841 is designated as epitype, since we were unable to locate recent material from England despite diligent search. This material was part of the description in Noordeloos (1979). For a full description refer to Noordeloos (1979).

/Dysthales subclade

This large basal subclade within subgen. Pouzarella (Fig. 28) is well-supported (ML 99 %) and contains E. dysthales and E. dysthaloides as well as several other, mainly unnamed lineages.

Entoloma dysthaloides Noordel., Persoonia 10(2): 219. 1979. MB 313709. Fig. 34.

Fig. 34.

Entoloma dysthaloides (A. LE F-331584; B–G. L0053995, isotype). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E. Hairs on pileus. F. Hairs on stipe. G. Pileipellis. Photo: L. Kalinina. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Typus: Austria, Bludenz, on soil in forest, 6 Jul. 1977, M. Moser, 77/44 (holotype, IB; isotype L0053995); ITS sequence, GenBank PX440386 (not included in the phylogenetic analysis).

Description: Basidiomata mycenoid. Pileus 4–12 mm wide, concico-convex with involute then straight margin, not hygrophanous, dark grey brown or almost black, minutely radially fibrillose to subsquamulose with slightly paler fibrils. Lamellae distant (L = 20–25, l = 1–3), narrowly adnate to adnate-emarginate, thickish, very dark grey without distinct pink tinge, with entire, concolourous edge. Stipe 15–20 × 1–2.5 mm, cylindrical, concolourous with pileus, covered with silvery fibrils lengthwise, minutely hairy all over with paler, patent hairs, base pale brown, woolly-strigose. Context thin, brittle, dark brown. Smell and taste indistinct. Basidiospores (110/5) 9.0–15.5 × 6.5–9.0 μm, on average 12.0–12.5 × 7.6–7.9 µm, Q = 1.30–1.90, Qav = 1.50–1.60, heterodiametrical, 6–9-angled, subnodulose in side view with thickened walls. Basidia 35–60 × 10–20 µm, 4-spored, clampless, with necropigment. Lamella edge sterile. Cheilocystidia 20–60 × 13–45 µm, septate, terminal elements narrowly to broadly clavate or vesiculose or more or less fusiform, with thickened, brown encrusted walls. Pileipellis a cutis of repent, 4–18 µm wide hyphae, with broader, up to 25 µm wide, clavate to fusiform terminal elements and coarsely encrusted walls. Stipitipellis a cutis of 7–14 µm wide hyphae, with patent multiseptate hairs, gradually broadening towards apex, with clavate terminal elements up to 25 µm wide, with brown encrusted walls. Clamp-connections absent from all tissues.

Habitat and distribution: Among forest litter in broad-leaved forests, with trees such as Betula, Corylus, Quercus, and Tilia, partly dry calcareous sites, partly moist places. Probably widespread, but overlooked, and confused with similar species.

Additional material examined: Norway, Innlandet, Hedmark, Tynset, Nytrøya, along Gløta river, on muddy soil near Betula, 17 Jul. 1979, M.E. Noordeloos, 974 (L0607228); Telemark, Porsgrunn, Frierflogene, Frierstien, calcareous forest with much Corylus, 6 Sep. 2012, T. Læssøe & A. Molia ,AM-238b-2012 (O-F-245311). Russia, Leningrad Oblast, Lomonosovsky District, Orzhytsy Village, on soil in abandoned park with broad-leaved trees (Quercus robur, Ulmus sp., Acer platanoides, Tilia cordata), 31 Jul. 2018, L. Kalinina, LE F-331584. The Netherlands, prov. Limburg, Gronsveld, Savelsbos, terrestrial in mixed broad-leaved forest on calcareous loam, 11 Sep. 1977, J. Schreurs & M.E. Noordeloos (L44013661).

Notes: In general, old collections of Pouzarella species are quite hard to sequence and thus we have not been able to sequence the isotype of E. dysthaloides with Sanger method, but within the frame of the FunDive project (https://fun-dive.eu/) using NGS method (Illumina), the ITS2 of the isotype was successfully sequenced and it corresponds well with our current concept of the species. Unfortunately, a good photograph of sequenced material is still lacking.

Entoloma hirsutum Noordel., Trendel, Karich & Dima sp. nov. MB 860433. Fig. 35.

Fig. 35.

Entoloma hirsutum (A. L0607306, holotype; B–F. GLM-F139006). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E. Caulocystidia. F. Pileipellis. Photos: A by J.F.M. Trendel; B–F by A. Karich. Scale bars: 1 cm (habit), 10 μm (all other figs).

Etymology: hirsutus (Lat.) – shaggy, roughly, bristly, referring to the aspect of the pileal surface.

Typus: France, Grand Est, Alsace, Offendorf, Reserve Naturelle Nationale de la Foret d’Offendorf, in grassy roadside near Quercus, 19 Aug. 2019, J.-M. Trendel, JMT-19081915 (holotype L0607306); ITS sequence, GenBank PX412039.

Description: Basidiomata mycenoid. Pileus 10–15 mm wide, conio-convex, blackish brown to greyish brown, pallescent from centre to dark brown, slightly hygrophanous, translucently striate up to half the radius when fresh, then opaque, ribbed on the back of the lamellae, minutely felted-fibrillose with silvery fibrils, contrasting with the background. Lamellae distant (L = 20–24, l = 5–9), adnate-emarginate, segmentiform to ventricose, dark grey pink with fimbriate, concolourous or slightly paler edge. Stipe 20–60 × 1–3 mm, concolourous with pileus, minutely felted-fibrillose all over, at base with dark setose hairs. Context thin, brittle, concolorous with surface. Smell and taste indistinct. Basidiospores (60/3) 9.5–14 × 6.5–8.0 μm, on average 10–12.5 × 6.9–7.5 μm, Q = 1.45–2.00(–2.10), Qav = 1.55–1.80, nodulose-angular. Basidia 25–45 × 8–12 μm, 4-spored, many sclerobasidia present. Lamella edge sterile with clavate to fusiform cheilocystidia with brown coloured, strongly brown encrusted walls. Pileipellis a cutis with transitions to a trichoderm of long, septate, 8–15 μm hyphae, strongly brown encrusted, with tapering or subclavate thin-walled, usually non-encrusted terminal elements. Stipitipellis a cutis of 8–15 μm wide, more or less cylindrical, encrusted hyphae. Caulocystidia 30–100 × 8–25 μm, flexuose, subclavate or subcylindrical, non-encrusted. Clamp-connections absent.

Habitat and distribution: On soil amongst litter or in grass in roadside verges near Quercus, on loamy soils, the German collection in an old limestone quarry with Populus tremula, Acer platanoides, some Betula pendula and Corylus avellana, and with only Corylus. Known from France, Germany, and The Netherlands.

Additional material examined: Germany, Sachsen, Schöpstal, Kalkbruch, in an old limestone quarry with Populus tremula, Acer platanoides, some Betula pendula and Corylus avellana, and with only Corylus, 5 Oct. 2022, A. Karich & R. Ullrich, IHI-22Ent05 (GLM-F139006). The Netherlands, prov. Limburg, Venlo, terrestrial among grasses and humus near Quercus, 12 Jul. 1986, G.M. Gatzen (L4401131).

Notes: Entoloma hirsutum can be distinguished by the narrow spores, strongly membranal encrusted cheilocystidia, and non-encrusted caulocystidia. Entoloma hirtum is close, with similar caulocystidia, different cheilocystidia and somewhat broader spores.

Entoloma hirtum (Velen.) Noordel., Persoonia 10(2): 223. 1979. MB 313733. Fig. 36.

Fig. 36.

Entoloma hirtum (A. L0607305, epitype; B. GLM-F139003; C–F. Holotype). A, B. Habit. C. Basidiospores. D. Cheilocystidia. E. Hairs of stipe. F. Hairs of pileipellis. Photos: A by J.F.M. Trendel; B by A. Karich. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (all other figs).

Basionym: Nolanea hirta Velen., Mykologia 6(2–3): 25. 1929. MB 267208.

Typus: Czechia, Central Bohemia, Radotín, calcareous grassland, Jun. 1926, J. Velenovský (holotype, PRM). France, Grand Est, Alsace, Dalgrunden, in litter in broad-leaved forest, 15 Oct. 2017, J.-M. Trendel, JMT17101507 (epitype L0607305, designated here, deposited at L, MBT 10028208); ITS sequence, GenBank PX412040.

Description: Basidiomata mycenoid. Pileus 10–30 mm wide, 10–15 mm high, conical, conico-campanulate, expanding to conico-convex, surface very dark grey to grey brown, entirely finely fibrillose-subsquamulose with adpressed or slightly uplifted, silvery shiny, fibrillose patches, contrasting with the background, slightly hygrophanous, obscurely translucently striate up to about half or two thirds of the pileal radius, sometimes striate from the margin to the centre. Lamellae distant (L = 20–25, l = 3–7), adnate-deeply emarginate, ventricose, grey brown with concolourous or slightly paler edge. Stipe 20–80 × 2–3 mm, cylindrical, concolourous or slightly paler than pileus, strongly fibrillose-striate, sometimes twisted, and finely pruinose to hairy with silvery patent hairs; with a yellowish brown or reddish brown strigose base. Context thin, concolourous with surface, brittle. Smell indistinct, taste not noted. Basidiospores (120/5) (10.0–)10.5–13.0(–14.5) × (6.0–)6.5–8.0 μm, on average 11–12 × 7.0–7.7 μm, Q = 1.40–1.90, Qav = 1.50–1.60, heterodiametrical, 6–9-angled-nodulose in side view. Basidia 2- and 4-spored, clampless. Lamella edge sterile. Cheilocystidia 30–60 × 15–25 μm, ellipsoid to clavate or subfusiform, rather thin-walled. Pleurocystidia absent. Hymenopodium indistinct, not much differentiated from trama, not encrusted. Pileipellis a transition between a cutis and a trichoderm made up of septate hyphae, with subcylindrical to fusiform terminal elements, with yellowish brown, sparsely encrusted walls. Stipitipellis a cutis with numerous caulocystidia, usually 2–3 septate, with irregularly clavate, utriform or lageniform terminal elements, and brown, non-encrusted walls. Clamp-connections absent.

Habitat and distribution: In thermophilous, semi-natural grasslands on calcareous soil, in litter in Crataegus copse in coastal dunes, or in litter in broad-leaved forest. Sequence based records known from France, Germany, Italy (ITS sequence, GenBank KF321786), and The Netherlands.

Additional material examined: Germany, Sachsen, Hainewalde, Gampenstein, 19 Sep. 2022, A. Karich, IHI-22Ent04 (GLM-F139005); Thüringen, Krölpa, Buchberg; calcareous thermophilic grassland, 10 Oct. 2019, A. Karich, IHI-19Ent05 (GLM-F139003). The Netherlands, prov. Noord Holland, Wijk aan Zee, 2 Nov. 2023, E. Brouwer (L0607290).

Notes: The concept of E. hirtum coincides with that of Noordeloos (1979) and Battistin et al. (2013b). It is distinguished from the closely related E. hirsutum mainly by the slightly broader spores, less strongly encrusted hyphae, and non-encrusted caulocystidia. It also occurs in rather dry grassland habitat besides forests. Entoloma hirsutum is very similar, and has slightly narrower spores, and somewhat more pronouncedly encrusted cheilocystidia. Whether these morphological differences stand when more material is studied, needs to be seen. Probably one should consider these two taxa as barcode (“cryptic”) species. Records in literature must therefore be treated with care. Both E. hirtum and E. hirsutum differ from other species in sect. Dysthales by the non-encrusted caulocystidia.

Entoloma pilosum G.M. Jansen, M.v.d. Vegte & Noordel., sp. nov. MB 860434. Fig. 37.

Fig. 37.

Entoloma pilosum (L4343929, holotype). A, B. Habit. C. Basidiospores. D. Cheilocystidia and basidium. E. Surface of stipe. F. Pileipellis. Photos: A, C–F by G.M. Jansen; B by M.J.C. van der Vegte. Scale bars: 1 cm (habit), 10 μm (microstructures).

Etymology: pilosus (Lat.) hairy, referring to the surface of the pileus and stipe.

Typus: The Netherlands, prov. Gelderland, Rheden, Heiderust, in moss rich grassy spot on a graveyard, 5 Aug. 2023, M.J.C. van der Vegte & G.M. Jansen (holotype L4343929); ITS sequence, GenBank PX412057.

Description: Basidiomata mycenoid. Pileus 7–16 mm wide, conico-convex to convex, not hygrophanous, not translucently striate, grey brown, sometimes grooved on sides of lamellae, densely hairy fibrillose. Lamellae distant, (L = about 20, l = 1–3), narrowly adnate-emarginate, ventricose, grey brown with white, fimbriate edge. Stipe 25–60 × 1–3 mm, grey brown, felted-hairy all over like pileus, with pale ochre basal mycelium. Context thin, brittle, brown. Smell and taste indistinct. Basidiospores (40/2) 10.0–18.0 × 8.0–10.0 μm, on average 12.5–15.0 × 8.0–8.3 μm, Q = 1.30–2.10, Qav = 1.45–1.80, heterodiametrical, irregularly 8–10-angled, almost nodulose, relatively thick-walled, brown in water. Basidia 45–60 × 9–15 μm, 2- and 4-spored. Lamella edge sterile. Cheilocystidia 46–70 × 15–32 μm, elliptical to clavate, thick-walled, encrusted with brown pigment. Hymenophoral trama with well-developed mediostratum of narrow hyphae. Pileipellis a cutis with transitions to a trichoderm, made up of cylindrical, septate, 5–20 μm wide hyphae, with fusiform to clavate terminal elements, 25–90 × 5–20 μm. Stipitipellis a cutis with transitions to a trichoderm, of 6–22 μm wide, septate hyphae, with fusiform terminal elements, 30–65 × 5–20 μm. All hyphae of pileipellis, pileitrama and stipitipellis strongly brown encrusted. Clamp-connections absent.

Habitat and distribution: Terrestrial, on unpaved roadside in a cemetery, and amongst litter in Populus plantation on clay or with Crataegus. So far only known from The Netherlands.

Additional material examined: The Netherlands, prov. Zeeland, Oostburg, de Plaote, amongst litter in Populus plantation, 31 Jul. 1980, A. de Meyer, 124 (L4401128).

Notes: Despite the large barcode gap between E. dysthaloides and E. pilosum, they are morphologically very similar. The spore size of E. pilosum is, however, somewhat larger, more or less intermediate between E. dysthales and E. dysthaloides, but more material is needed to evaluate these differences.

/Rusticoides clade – subgenus Omphaliopsis

Entoloma subgenus Omphaliopsis Noordel., Persoonia 11: 148. 1981. MB 90830, amend.

Synonym: Rhodophyllus sect. Clitopiloides Romagn., Beih. Nova Hedwigia 59: 71. 1978. MB 562984.

Entoloma sect. Clitopiloida (Romagn.) Noordel., Persoonia 11: 139. 1981. MB 543690.

Clitopiloides (Romagn.) Largent, Entolomatoid fungi of the Western United States and Alaska (Eureka): 30. 1994. MB 543690.

Omphaliopsis (Noordel.) P.D. Orton, Mycologist 5(4): 173. 1991. MB 25334.

Type species: Rhodophyllus leptonipes Kühner & Romagn. = Entoloma incarnatofuscescens (Britzelm.) Noordel.

The /Rusticoides clade coincides with Entoloma subgenus Omphaliopsis (Fig. 38). This clade contains species with a predominantly omphalinoid to clitopiloid basidiomata, often isodiametrical spores, encrusting pigment and clampless hyphae. It is amended here by including E. sericeoides, formerly included in subgen. Clitopiloida, which now is considered synonymous with Omphaliopsis. Ecologically the species in this clade are also rather specialised, as most prefer rather exposed habitats, on bare (mineral) soil or in places with scanty vegetation, such as roadsides, gardens, coastal dunes, (sub-) alpine moraine and other exposed habitats, xerophytic grassland, and Mediterranean shrub vegetation. An extensive study has been published by Vila et al. (2014), which we reflect upon, with some updates and amendations, including typifications. The typification of E. incarnatofuscescens was discussed in Noordeloos et al. (2022a, b). Subgenus Omphaliopsis also includes the gasteroid E. vallibacense (Vidal et al. 2016).

Fig. 38.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma subgen. Omphaliopsis (= /Rusticoides clade). ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma bresadolae O.V. Morozova, Noordel., Reschke, Bendiksen, K. Potapov & A. Filippova, sp. nov. MB 860438. Fig. 39.

Fig. 39.

Entoloma bresadolae (A–I, K, L. LE F-343756, holotype; J. LE F-343755). A–C. Habit. D, G. Basidiospores. E, H. Basidia. F, I, J. Cheilocystidia. K. Pileipellis. L. Caulocystidia. Photos: O. Morozova. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Etymology: Named in honour of Giacomo Bresadola (1847–1929), an eminent Italian mycologist, author of 1017 species of fungi including some representatives of Entoloma subgenus Omphaliopsis.

Typus: Russia, Sverdlovsk Oblast, Nizhneserginsky District, Arakaevo Village, “Deer Creeks” Nature Park, left bank of the Serga River, on soil in steppe meadow, 23 Aug. 2024, A. Filippova & O. Morozova, 128SV24 (holotype LE F-343756); ITS sequence, GenBank PX412026.

Description: Basidiomata omphalinoid. Pileus 7–15 mm wide, depressed in centre, with slightly involute then straight, sometimes crenate margin, hygrophanous, more or less translucently striate, distinctly squamulose, more densely so in the centre, when moist dark yellow brown, or sepia with darker centre, pallescent on drying. Lamellae moderately distant (L = 12–18, l = 1–4), broadly adnate-decurrent, arcuate to segmentiform, pale brown, beige then pinkish brown with entire concolourous edge. Stipe 10–20 × 1.5–2 mm, cylindrical or slightly broader towards the base, yellow brown with greyish tinge towards the base, smooth, glabrous, solid then fistulose. Context concolourous with surface. Smell indistinct. Taste not reported. Basidiospores (100/6) 7.2–8.6 × 6.4–7.5 μm, on average 8.1–8.3 × 7.0–7.3 µm, Q = 1.0–1.30, Qav = 1.15–1.20, subisodiametrical, with 5–7 weak angles in side view. Basidia 32–35 × 11–12 µm, 2–4-spored, clampless. Lamella edge sterile or heterogeneous. Cheilocystidia 24–35 × 7.5–20 µm, clavate, broadly clavate, sphaeropedunculate or lageniform. Pileipellis a cutis of radially arranged, 5–8 µm wide hyphae, with transition to a trichoderm with ascending inflated, 15–25 µm wide hyphae with clavate or sphaeropedunculate (54–77 × 29–25 µm) or also fusiform (60–95 × 18–37 µm) terminal elements; subpellis made up of long, inflated, 5–20 µm wide elements. Hymenophoral and pileitrama regular, made up of long, cylindrical 5–10 µm wide hyphae. Pigment abundant in pileipellis and pileitrama, mostly brown and intracellular, sometimes agglutinate, additionally distinctly encrusted. Stipitipellis consisting of cylindrical, 6–8 µm wide hyphae, sometimes encrusted. Caulocystidia present in upper part of the stipe, similar to cheilocystidia, clavate or sphaeropedunculate. Clamp-connections absent.

Habitat and distribution: In xerophytic grasslands or in steppes on sandy, clayey or calcareous soil (one site with semi-natural, mown/grazed grassland). Reported from European Russia including the Ural Mountains, Norway and Spain.

Additional material examined: Norway, Akershus, Nesodden: Steilene, on soil in open, calcareous, near-shore grassland with shallow soil, 14 Oct. 2006, E. Bendiksen, EB 232/06 (O-F-253960); Buskerud, Drammen, Ryghsetra, on soil in calcareous semi-natural, mown meadow, 11 Aug. 1998, G. Gulden, 121/98 (O-F-72081); Innlandet, Oppland, Dovre, Dombås, Hjellhågån, on sand dunes by the river Gudbrandsdalslågen, 11 Aug. 2017, P.G. Larsen & D. Holtan, PGL110817 (O). Russia, Tatarstan Republic, 23 Sep. 2013, K. Potapov, PK11731 (LE F-343757); Kurgan Oblast, Petukhovsky District, shore of the Medvezhiye lake, salted burnt steppe, on soil, 19 Jul. 2016, O. Shiryaeva, 107-07-16 (LE F-343755).

Notes: Entoloma bresadolae phylogenetically is sister to E. phaeocyathus, which, however, usually has larger and darker basidiomata and significantly larger spores. The name E. phaeocyathus has historically been misapplied to this species in Norway, in red data lists, management documents and species databases. The new species differs from E. ludwigii, which occurs in the same habitats and is very similar in appearance, by its hygrophanous, not completely fibrillose pileus, longer stipe, and also by less pronounced incrustations in the pileipellis hyphae.

Entoloma flocculosum Bres. ex Pacioni, Micol. Veg. Medit. 2(2): 148. 1988. MB 133932. Fig. 40.

Fig. 40.

Entoloma flocculosum [A. Lectotype (Bresadola 1929); B–D, F–K. LE F-18949; E. DB-2020-06-25-1). A, E. Habit. B, F. Basidiopores. C, G, H. Basidia. I. Cheilocystidia. J. Lamellae edge. K. Pileipellis. Photos: E by I. Ölvedi; F–K by O. Morozova. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Replaced synonym: Leptonia flocculosa Bres., Iconogr. Mycol. 12: tab. 577(1). 1929. MB 373505, nom. illegit., Madrid, Art. 52.1.

Typus: Bresadola (1929), Iconogr. Mycol. 12: tab. 577(1) (lectotype, designated here, MBT 10028213).

Description: Basidiomata omphalinoid to collybioid. Pileus 8–15 mm wide, hemispherical then convex, with distinctly depressed centre, with deflexed, or straight margin, not hygrophanous or translucently striate, when moist very dark reddish brown to grey or blackish brown, entirely finely floccose to squamulose with pointed squamules. Lamellae moderately distant (L = 12–15, I = 1–3), broadly adnate, usually with small decurrent tooth, dark brown concolourous pileus then with pink tinge, with entire, concolourous edge. Stipe 6–15 × 0.5–2 mm, cylindrical or with attenuate base, concolourous with pileus or slightly paler, smooth, almost glabrous or with scattered whitish fibrils. Context thin, brittle, brown. Smell and taste unknown. Basidiospores (60/3) 7.5–9.5 × 6.6–8.7 µm, on average 8.2–9.0 × 7.8–8.5 µm, Q = 1.00–1.20, Qav = 1.10, subisodiametrical to isodiametrical, with 6–8 weak angles in side view, almost rounded in outline. Basidia 4-, rarely also 2-spored, clampless. Lamella edge fertile or heterogeneous. Cheilocystidia mostly absent but some weakly differentiated septate cells can be present on lamellar edge. Pileipellis a cutis with transitions to a trichoderm, made up of repent to ascending, cylindrical, up to 20 µm wide hyphae with more or less clavate terminal elements, 30–70 × 15–25 µm. Pigment dark brown, strongly encrusting the hyphae of pileipellis and upper pileitrama, often zebra striped, and in addition intracellular. Clamp-connections absent.

Habitat and distribution: On soil in short-grazed grassland and in xerophytic grassy vegetation (steppe), preferably on calcareous soils. Widespread but rare, known so far from Italy, Hungary, Russia and Spain.

Additional material examined: Hungary, Pest, Csévharaszt, on sandy soil with Pinus and Populus, 25 Jun. 2020, I. Ölvedi, DB-2020-06-25-1 (ELTE). Russia, Penza Oblast, Neverkinsky District, “Privolzhskaya Lesostep” Nature Reserve, Kuncharovskaya steppe, on soil, 3 Aug. 1990, A.I. Ivanov (LE F-18949). Spain, Catalunya, Serrat de l’Artigot, la Quar (Barcelona), 780 m.a.s.l., on basic soil among lichens and mosses, under Satureja montana, near Buxus sempervirens, 20 Sep. 2008, J. Vila & F. Caballero, JVG 1080920-20 (LIP) (Vila et al. 2014).

Notes: Leptonia flocculosa is an illegitimate name as it included the type of the older name Eccilia watsonii (Peck) Sacc. Pacioni ‘combined’ this illegitimate name to Entoloma, which is not admissible, because the basionym of a legitimate new must be legitimate. However, according to the Madrid Code Art. 6.12 (a) and 6.14 the stated ‘comb. nov.’ is to be treated as a correctable error and, thus, the name Entoloma flocculosum was introduced by Pacioni as a nomen novum for the illegitimate name L. flocculosa. As the description by Bresadola is referred to, the requirements for valid description are fulfilled. Among other xerophytic species with small, more or less omphalinoid basidiomata, E. flocculosum is recognized by almost non-decurrent lamellae, non-hygrophaneous pileus and by spores with rounded outlines with weak angles.

Entoloma incarnatofuscescens (Britzelm.) Noordel., Persoonia 12(4): 461. 1985. MB 104243.

Basionym: Agaricus incarnatofuscescens Britzelm., Hymenomyceten aus Südbayern 10(VII): 6. 1894. MB 372150.

Synonyms: Entoloma klofacianum Noordel., Wölfel & Hauskn., Öst. Z. Pilzk. 4: 128. 1995. MB 413018.

Entoloma violaceoparkensis Noordel. & Trichies, in Noordeloos, Entoloma s.l., Fungi Europaei vol. 5a: 1120. 2004. MB 491870.

Rhodophyllus leptonipes Kühner & Romagn., Rev. Mycol. 19(1): 6. 1954. MB 305239.

Material examined: France, Seine et Oise, Yerres, Sep. 1932, H. Romagnesi, 32.12 (holotype of Rhodophyllus leptonipes, PC); ITS sequence, GenBank PX444434.

Notes: Entoloma incarnatofuscescens has been neotypified in Noordeloos et al. (2022b), with a full description given. Rhodophyllus leptonipes was listed as a synonym with question mark, because we did not have molecular proof by that time. Recently, we successfully obtained ITS from the holotype, which was shown to be identical with the neotype of E. incarnatofuscescens, which now confirms the synonymy.

Entoloma ludwigii O.V. Morozova, Noordel., Reschke, Dima, O. Shiryaeva & I. Gorbunova, sp. nov. MB 860437 Fig. 41.

Fig. 41.

Entoloma ludwigii [A, D–I, K. Holotype; B. LE F-254381; C. Ludwig 2399A (Ludwig 2007); J. LE F-343759]. A–C. Habit. D, H. Basidiopores. E, G. Basidia. F. Cheilocystidia. I. Lamellae edge. J. Stipitipellis. K. Pileipellis. Photos: O. Morozova. Drawings: C by E. Ludwig; D–F by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Misapplied name: Entoloma flocculosum sensu Ludwig (2007).

Etymology: Named in honour of Erhard Ludwig (1938–2019), German mycologist and master painter, remembered for his monumental Pilzkompendium with beautiful drawings, in particular, of Entoloma.

Typus: Russia, Sverdlovsk Oblast, Nizhneserginsky District, near Arakaevo Village, “Deer Creeks” Nature Park, left bank of the Serga River, on soil in steppe meadow, 23 Aug. 2024, A. Filippova & O. Morozova, 131SV24 (holotype LE F-343758); ITS sequence, GenBank PX412046.

Description: Basidiomata omphalinoid. Pileus 10–20 mm wide, depressed to umbilicate, with initially involute then rather straight margin, not hygrophanous, not translucently striate or striate at the pileus margin only, radially fibrillose to subsquamose, when moist dark grey brown, sepia, yellow brown, pallescent on drying. Lamellae moderately distant (L = 12–20, l = 1–5), broadly adnate-decurrent, arcuate to segmentiform, pale brown then dark pinkish brown with entire concolourous edge. Stipe 10–15 × 2–3 mm, cylindrical or slightly broader towards the base, grey brown or yellow brown, concolourous with the pileus, smooth, almost glabrous or slightly fibrillose-striate lengthwise, solid then fistulose. Context concolourous with surface. Smell indistinct. Taste not reported. Basidiospores (140/6) 7.5–9.4 × 6.0–8.0(–8.5) μm, on average 8.1–8.5 × 7.1–7.6 µm, Q= 1.0–1.30, Qav = 1.15–1.20, subisodiametrical, with 5–7 weak angles in side view. Basidia 30–35 × 10–11 µm, 4-spored, clampless. Lamella edge sterile, heterogeneous or fertile. Cheilocystidia 22–32 × 11.5–17 µm, clavate, broadly clavate, sphaeropedunculate or lageniform, sometimes absent. Pileipellis a cutis of radially arranged, 2.5–8 µm wide hyphae, with transition to a trichoderm with ascending clavate terminal elements, 48–96 × 15–25 µm, subpellis made up of long, inflated, 5–20 µm wide elements. Hymenophoral and pileitrama regular, made up of long, cylindrical 5–10 µm wide hyphae. Pigment abundant in pileipellis and pileitrama, distinctly encrusting, sometimes arranged spirally or resembling zebra stripes, but also brown and intracellular. Stipitipellis of cylindrical, 6–8 µm wide hyphae 6–8 µm broad, sometimes encrusted. Caulocystidia similar to the cheilocystidia, clavate or lageniform, septate, composed of inflated cells up to 15 µm broad with lageniform terminal elements. Clamp-connections absent.

Habitat and distribution: In poor xerophytic grasslands or in steppes on sandy, clayey or calcareous soil. Reported from Germany and both European and Asian Russia.

Additional material examined: Germany, Brandenburg, Lebus, Nature reserve, in road-side on sandy soil among Deschamptia, 2 Sep. 1994, W. Dieckow, Ludwig Herb. Nr. 2399A (M) (Vila et al. 2014). Hungary, Fejér County, Vértes Mts, Csákberény, 18 Sep. 2014, P. Finy, FP-2014-09-18-1 (ELTE). Russia, Novgorod Oblast, Batetsky District, near Ivnya Village, river bank, on sandy soil, 19 Sep. 2012, O. Morozova (LE F-254381, as E. flocculosum); Sverdlovsk Oblast, Nizhneserginsky District, Arakaevo Village, “Deer Creeks” Nature Park, left bank of Serga River, on soil in steppe meadow, 23 Aug. 2024, A. Filippova & O. Morozova, 129SV24 (LE F-343759); Kurgan Oblast, Petukhovsky District, shore of the Medvezhiye lake, salted burnt steppe, on soil, 19 Jul. 2016, O. Shiryaeva, 106-07-16 (LE F-343722); Altai Republic, Kosh-Agach District, near Kurai Village, right bank of the River Chuya, steppe, on soil, 26 Jun. 2014, I. Gorbunova, 06260062-63 (LE F-343723).

Notes: This species differs from the closely related E. flocculosum by more decurrent lamellae, smaller spores and often also by the presence of cheilocystidia. Entoloma ludwigii was considered by Ludwig (2007) as E. flocculosum and has been included in the wide concept of E. flocculosum in Vila et al. (2014).

Entoloma polyangulatum Noordel. & Hauskn., Österr. Z. Pilzk. 18: 169. 2009. MB 515311. Fig. 42.

Fig. 42.

Entoloma polyangulatum (WU-Myc 27147, holotype). A. Habit. B. Basidiospores. C. Pileipellis. D. Cheilocystidia. Photo: A. Hausknecht. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Synonym: Entoloma phaeocarpum F. Caball. et al., Revista Catal. Micol. 35: 90. 2014. MB 807471.

Typus: Austria, Niederösterreich, Wolkersdorf im Weinviertel: Münichsthal, 29 Jul. 2001, T. Barta, Herbarium A. Hausknecht 2421.0 (holotype WU-Myc 27147); ITS sequence, GenBank PX412059.

Description (amended here): Basidiomata: omphalinoid. Pileus 5–15 mm wide, up to 7 mm high, hemispherical to plano-convex, sometimes with shallow depression at centre, with involute to deflexed margin, grey brown to dark brown, sometimes with blackish brown centre, micaceous-fibrillose to tomentose, with age becoming translucently striate at margin, and slightly hygrophanous, pallescent on drying. Lamellae moderately distant (L = 20–30, l = 1–3), broadly adnate or decurrent with tooth, very broadly ventricose, occasionally veined on sides, brown to greyish brown, then with lilac-pink tinges, with entire, concolourous lamellar edge. Stipe 15–22 × 1–3 mm, cylindrical, ochre grey, to greyish brown, finely pruinose at apex, downwards glabrous, polished. Context brown. Smell indistinct, sometimes slightly fruity, taste not recorded. Basidiospores 7.0–10.0 × 6.5–10.0 μm, on average 8.5–9.5 × 8.2–9.2 μm, Q = 1.00–1.20, Qav = 1.05–1.10, isodiametrical to subisodiametrical, rounded-polyangular with 5–9 weak angles, thin-walled. Basidia 20–60 × 7–16 μm, 4-spored, clampless. Lamellar edge fertile or heterogeneous. Cheilocystidia, if present, 20–42 × 5–11 μm, clavate, fusiform or lageniform, with refringent walls. Pileipellis a differentiated cutis of septate, cylindrical, 4–20 μm wide hyphae. Pigment brown, strongly encrusting the hyphae of pileipellis and pileitrama. Pileitrama regular, made up of medium-sized, up to 25 μm wide hyphal elements. Clamp-connections absent.

Habitat and distribution: On soil in thermophilous broad-leaved forest (in terms of E. polyangulatum) and in Mediterranean Pinus halepensis forest on sandy soil (E. phaeocarpum). Known from Austria and Spain.

Additional material examined: Spain, La Rioja, Calahorra, 18 Oct. 2003, A. Caballero (LIP JVG 1031018, holotype of E. phaeocarpum).

Notes: Type studies and ITS barcodes confirmed the synonymy of E. phaeocarpum with E. polyangulatum. This might be another more or less thermophilous southern(-eastern) “Rusticoides” species in Europe, but more material is needed to confirm ecological-chorological patterns.

Entoloma pseudosericeoides Hauskn. & Noordel., Österr. Z. Pilzk. 7: 244. 1998. MB 450561. Figs 43, 44.

Fig. 43.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences depicting the relationship of Entoloma sericeoides and E. pseudosericeoides within subgen. Omphaliopsis (= /Rusticoides clade) using additional sequences not included in Fig. 38. ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Fig. 44.

Entoloma pseudosericeoides (A, D, G. L0607182; B. VidraGy-2019-05-21-1; C. DB106-19; E. VidraGy-2019-05-25-1; F. SzEr-2017-05-14; H. Holotype). A–F. Habit. G. Basidiospores. H. Cheilocystidia. Photos: A, D, G by M. Dondl; B, E by Gy. Vidra; C by B. Dima; F by Er. Szabó. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Typus: Austria, Niederösterreich, Maissau, in garden with Thuja, Chamaecyparis and Pinus mugo, 19 Jun. 1993, A. Hausknecht (holotype WU 18082, isotype in L); ITS sequence, GenBank PX440388.

Description: Basidiomata omphalinoid to clitocyboid. Pileus 10–35 mm broad, already when young deeply infundibuliform with inrolled margin, slightly hygrophanous, translucently striate in marginal zone only, uniformly dark brown, olivaceous brown to blackish brown; pallescent in radial streaks on drying to brown beige or grey brown, glabrous, at centre scurfy-subsquamulose. Lamellae crowded, slightly to deeply decurrent, narrow, pale grey brown then pink, with concolourous edge, which sometimes turns brown with age. Stipe 30–70 × 3–7 mm, cylindrical or compressed with or without slightly enlarged base, beige brown to greyish, sometimes with weak olivaceous tinge, finely longitudinally fibrillose striate to adpressed woolly-tomentose. Context thin, pale brown to olivaceous grey. Smell and taste spermatic, then farinaceous. Basidiospores (120/5) 7.2–8.7 × 6.0–6.8 µm, on average 7.5–7.6 × 6.5–6.7 µm, Q = 1.10–1.40, Qav = 1.15–1.25, subisodiametrical, 4–6 angled. Basidia 4-spored, clampless. Lamella edge heterogeneous. Cheilocystidia absent, sparse to abundant, mixed with basidia, 30–62 × 6–13 µm, cylindrical, clavate or lageniform. Pileipellis a cutis of cylindrical hyphae, 10–14 µm wide, with transitions to a trichoderm at centre, made up of inflated, 10–18(–22) µm wide, terminal elements. Pigment intracellular and also finely encrusting. Clamp-connections absent in all tissues.

Habitat and distribution: In woody places, along forest tracks, in gardens, in dry grasslands, and in alluvial mixed forests on calcareous and sandy soil. So far known from a few localities in Austria, Germany, and Italy (GenBank JF908006, as E. sericeoides) and from several places in Hungary.

Additional material examined: Austria, Steiermark, Landkreis Hartberg-Fürstenfeld, Hartberg, Ringwarte, along a brook with Acer, Fraxinus and Picea, 19 May 2019, B. Dima, A. Nagy & M. Fodor, DB-106-19 (ELTE). Germany, Landkreis Bad Tölz-Wolfratshausen, Icking, Isaruferweg, in alluvial forest (Fraxinus, Salix, Crataegus, Picea, Alnus, Acer) on sandy, gravelly soil, 28 May 2016, M. Dondl (L0607182). Hungary, Heves County, Heves–Borsodi Hills, Bükkszék, Csoma Mt, in Pinus sylvestris plantation, 14 May 2017, E. Szabó, SzEr-2017-05-14 (ELTE); Komárom-Esztergom County, Gerecse Mts, in grassland, 11 May 2019, Gy. Vrba, VGy-2019-05-11-1; Vértes Mts, in grassland, near Várgesztes, 18 May 2019, Gy. Vrba, VGy-2019-05-18-1; Veszprém County, Bakony Mts, Balatonfüred, in alluvial forest near Acer and Fraxinus, 16 Apr. 2019, M.K. Frits, DB-24-19 (ELTE); Várpalota, in park among grasses, 21 May 2019, Gy. Vidra, VidraGy-2019-05-21-1 (ELTE); ibid., in park among grasses, under Pinus nigra, 25 May 2019, Gy. Vidra, VidraGy-2019-05-25-1 (ELTE); ibid., in park among grasses, under Betula pendula, 25 May 2019, Gy. Vidra, VidraGy-2019-05-25-2 (ELTE).

Notes: Entoloma pseudosericeoides morphologically comes very close to E. sericeoides. Based on the material studied, it seems that E. pseudosericeoides has in average more infundibuliform, a slightly paler brown, and often distinctly translucently striate pileus, sometimes up to the half. Entoloma sericeoides has a glabrous pileus, and lacks cheilocystidia, which are, however, present and abundant in the holotype of E. pseudosericeoides, but apparently absent in the German collection. According to our data, the species fruits from spring (April, May) to early summer (June) and may have on average more southern distribution than that of E. sericeoides.

Entoloma pumilionis Reschke, O.V. Morozova, Noordel., Dima, Hülsewig & E.S. Popov, sp. nov. MB 860436. Fig. 45.

Fig. 45.

Entoloma pumilionis (A, B, D–F. B 70 0105497, holotype; C. LE F-254253). A–C. Habit. D, E. Basidiospores. F. Pileipellis. Photos: A, B by T. Hülsewig; C by E. Popov; D–F by K. Reschke. Scale bars: 1 cm (habit), 10 μm (microstructures).

Etymology: pumilio (Lat.) – dwarf, referring to the size of the basidiomata.

Typus: Germany, Nordrhein-Westfalen, Witten, Hohenstein, roadside, on rich soil, 5 Nov. 2022, T. Hülsewig, 1027, ACN50 (holotype B 70 0105497); ITS sequence, GenBank PX412063.

Description: Basidiomata collybioid to omphalinoid. Pileus 1–3 mm wide, initially convex, soon becoming umbilicate, with involute, slightly to deeply undulating margin, pale greyish brown to medium brown, darker, brown to dark brown towards the centre, not translucently striate in young basidiomata, sometimes soon becoming translucently striate, especially in paler basidiomata, covered with fine, whitish, fibrillose scales, often less fibrillose-scaly towards the margin. Lamellae moderately distant (L = 6–12, l = 1–5), moderately to deeply decurrent, with concolourous, entire edge. Stipe 1–5 × 0.2–0.4 mm, cylindrical, pale to moderately dark greyish brown, partly covered by white fibrillose-flocculose tufts, with white, cottony base. Context very brittle, brown. Smell not perceptible, taste not noted. Basidiospores (120/5) 8.0–10.0(–11.5) × 7.5–9.5 µm, on average 8.7–9.2 × 8.1–8.9, Q = 1.00–1.20(–1.40), Qav = 1.10-1.15, isodiametrical to subisodiametrical, rounded-angular, with 6–9 rather indistinct angles. Basidia (22–)26–40 × 9.5–12(–18.5), mainly 4-spored, some 2-spored, clampless. Lamella edge fertile, cystidia absent. Pileipellis a cutis at the margin, often with transitions to a trichoderm towards centre, composed of cylindrical to inflated, 5–30 µm wide hyphae with repent to somewhat erect or ascending terminal elements, 55–170 × 15–30 µm. Subpellis not distinctly developed. Hymenophoral and pileitrama regular, made up of narrow, cylindrical to broad, inflated elements, 4–32 µm wide. Stipitipellis a thin cutis of narrow, cylindrical hyphae. Caulocystidia not observed. Pigment brown, encrusting in pileipellis as well as in pileal and hymenophoral trama. Clamp-connections absent in all tissues.

Habitat and distribution: On soil in dry steppe communities or in anthropogenic habitats (road verges, gardens). Known from Germany, Hungary and Russia.

Additional material examined: Germany, Mecklenburg-Vorpommern, Malchin, Ferienanlage Salem, parking area, on soil, 4 Nov. 2022, V. Kummer, IHI-22Ent03 (GLM-F139802); Nordrhein-Westfalen, Witten, Hohenstein, wayside, on soil, 31 Oct. 2020, T. Hülsewig, 617, ACN48 (B 70 0105495). Hungary, Vas, Döröske, in garden, on soil among grass and mosses, G. Benkő & K. Fábrics, BG-2020-11-13-B4 (ELTE). Russia, Volgograd Oblast, Sredneakhtubinsky District, near Chapaevets Village, Volga-Akhtuba Floodplain Nature Park, on soil on slope with sparse grasses, Artemisia spp., and Populus shoots, 17 Oct. 2013, E.S. Popov ,ESP-000311 (LE F-254253).

Notes: Entoloma pumilionis is characterised by its tiny size and the not, or only somewhat translucently striate pileus. It has some resemblance to E. iodiolens, which has, however, larger basidiomata and an iodoform smell.

Entoloma rusticoides (Gillet) Noordel., Persoonia 11: 150. 1981. MB 112303. Fig. 46A–I.

Fig. 46.

A–I. Entoloma rusticoides (A. Gillet 1874–1898; B, C, G–I. L4343484, epitype; D. FP-2019-11-24-2; E, F. FP-2020-11-13-2). A–E. Habit (A. Lectotype). F, G. Basidiospores. H. Cheilocystidia. I. Pileipellis. J. Entoloma vilae (B 70 0105501, holotype). Habit. Photos: A by K. Reschke; B, C, G–I by G.M. Jansen; D–F by P. Finy; J by C. Manz & A. Gminder. Scale bars: 1 cm (habit), 10 μm (microstructures).

Basionym: Eccilia rusticoides Gillet, Les Hyménomycètes ou Description de tous les Champignons qui Croissent en France: 425. 1876. MB 185876.

Synonyms: Entoloma graphitipes E. Ludw., Pilzkompendium (Eching) 2([2]): 290. 2007. MB 548552.

Entoloma graphitipes f. cystidiatum Ferr. Caball., Vila & Català, Revta Catal. Micol. 35: 78. 2014. MB 807473.

Typus: Gillet, Les Hyménomycètes ou Description de tous les Champignons qui Croissent en France: pl. 276 (1874–1898) (lectotype, designated here, MBT 10028211). The Netherlands, prov. Gelderland, Rheden, Heiderust, among mosses in an old graveyard on sandy soil, 28 Dec. 2019, M. Plekkenpol, M.J.C van der Vegte & G.M. Jansen (epitype L4343484, designated here, deposited at L, MBT 10028212); ITS sequence, GenBank PX412065.

Description: Basidiomata omphalinoid. Pileus 8–20 mm wide, convex with depressed centre, with straight margin, hygrophanous, deeply translucently striate up to ½ the radius when moist, brown with slightly darker centre, pallescent on drying, with fibrillose covering. Lamellae distant (L = 14–20, l = 4–6), shortly decurrent, with furcations, pale brown when young then brown pink with concolourous, entire edge. Stipe 15–45 × 1–2 mm, cylindrical, glabrous, pale brown to dark brown, slightly darker towards base, base covered with white mycelium. Context thin, brown. Smell insignificant, taste not noted. Basidiospores (210/9) 7.5–10.0 × 6.0–8.0 μm, on average 8.4–8.7 × 6.8–7.1 μm, Q = 1.10–1.40(–1.45), Qav = 1.18–1.25, isodiametrical to shortly heterodiametrical, 5–6-angled in side view. Basidia 33–45 × 10.5–13.5 μm, clavate, 4-spored, clampless. Lamella edge sterile, heterogeneous or fertile. Cheilocystidia 20–60 × 4–10 μm, septate, hyaline, terminal element conical, lageniform or acutely conical. Pileipellis a cutis of cylindrical, 6–14 μm wide hyphae, with up to 15 μm wide, subclavate terminal elements with brown, finely encrusted walls. Pileitrama regular, made up of inflated hyphae, elements 100–350 × 5 × 40 μm with finely encrusted brown pigment. Stipitipellis a cutis of cylindrical hyphae, 4–15 μm, finely brown encrusted with irregularly shaped, subclavate terminal elements (“caulocystidia”). Clamp-connections absent.

Habitat and distribution: Terrestrial, in various grasslands, rarely in forests, mainly in dry places, among mosses, often on sandy soil. Widely distributed and not uncommon in Europe.

Description of the holotype of E. graphitipes: The holotype consists of 7 intact to somewhat fragmented basidiomata, with brown, convex to rather applanate pileus with distinct umbilicus, strongly decurrent, brown lamellae, and dark grey stipe. Microscopically the basidiomata are heavily infected by an Aspergillus sp. with largely collapsed vesicles, and dematiaceous hyphomycetes with didymospores and dictyospores. Basidiospores (20/1) 8.5–11.0(–12.0) × (6.5–)7.0–9.5(–10.0) µm, on average 9.6 × 8.2 µm, Q = (1.00–)1.10–1.35(–1.60), Qav = 1.18, subisodiametrical to broadly heterodiametrical, rarely completely isodiametrical, rarely relatively long heterodiametrical, 5–7-angled in side view, with rather weak, rounded angles. Basidia 4-spored as far as evaluable, clavate to broadly clavate, without clamp connection, generally few mature, intact basidia present. Absence or presence of hymenial cystidia not successfully evaluated. Pileipellis a cutis as far as evaluable, pigment difficult to locate, possibly parietal in some parts, some encrusting pigment present, but mainly at damaged and collapsed hyphae. Clamp-connections absent.

Additional material examined: Austria, Hirschegg, Kleinwalsertal, near Haus Marburg, forest edge of a Picea abies-dominated forest, on soil between moss and litter, 22 Sep. 2017, K. Reschke, KaiR920 (B 70 0105505). Germany, Bayern, Warngau, Taubenberg, Schwarzer Berg, on soil among Petasites and Urtica in mixed mountain forest of Fagus, Picea, and Abies, 6 Aug. 2016, M. Dondl (L0607944); Berlin, Berlin-Lichtenrade, children’s playground at the John-Locke street, on bare sand, partly between grasses, partly on an old fire site, 22 May 1982, E. Ludwig, 3348 (holotype of E. graphitipes, M-0159113); Hessen, Frankfurt, Wissenschaftsgarten, mesotrophic grassland, 17 Oct. 2016, K. Reschke, KaiR238 (B 70 0105503); Rheinland-Pfalz, Mainz, near Gonsenheim, grassland on rather sandy soil, 24 Nov. 2017, K. Reschke & W. Prüfert, KaiR1134 (B 70 0105510). Hungary, Bács-Kiskun, Bugac, Nagylegelő, on sandy cattle pasture, 24 Nov. 2019, P. Finy, FP-2019-11-24-2 (ELTE); Bócsa, in open sand dune, 13 Nov. 2020, P. Finy, FP-2020-11-13 (ELTE). Norway, Møre og Romsdal, Sunndal, Grøvudalen, Gammelsetra, moist grassland, 16 Sep. 1997, J.B. Jordal, JB97-404 (O-F-254408); Telemark, Bamble, Langesundstangen, open grassy spot in calcareous pine woodland, 15 Oct. 2012, A. Molia & T. Læssøe, AM-347i-2012 (O-F-245589). The Netherlands, prov. Gelderland, Rheden, Heiderust, in mossy lawn of churchyard, 22 Nov. 2017, M.J.C. van der Vegte & G.M. Jansen (L0608055).

Notes: Entoloma rusticoides is widely distributed, and the most common and best known species of subg. Omphaliopsis in Europe, thus this subgenus has also been called the /Rusticoides clade. Vila et al. (2014) designated an “epitype” for E. rusticoides using a specimen from a coastal Mediterranean habitat south of Tarragona, Spain, however, without indication of a holo-, lecto-, or neotype, so that this epitypification is nomenclatural ineffective (Madrid, Art. 9.9). Gillet (1876) published an illustration of Eccilia rusticoides, however, the publication date is difficult to trace. The text of the “Hyménomycètes” was consecutively published in three parts: 1874, 1876, and 1877 or 1878 (see Stafleu & Cowan 1976–1988, pp. 944–946). The description of Eccilia rusticoides was included in the second part. These parts were later bound together without changing the title page. The volume of the “Hyménomycètes” consulted for this study includes a separately paginated part “Liste de tous les champignons continues dans l’ouvrage sur les Hyménomycètes et rangés par ordre alphabétique” which provides page and plate numbers for each species. The plates were similarly published consecutively 1874–1898, while small parts of additional text, describing species for which so far only a plate had been published, were published 1884 and 1890 (Stafleu & Cowan, l.c.). The individual contents of the plate issues and their exact publication dates are not clear. It is possible that the plate of Eccilia rusticoides was published later than the text. However, the date of publication of the plate is nomenclaturally irrelevant (Madrid, Art. 9.4). The publication of the plates was announced in the text part and we have no reason to believe they were not existing at the time the text was published. There are understandable reasons that the plates were published at a comparably slow pace. The economy of the early French Third Republic was dominated by small family companies, with often fewer than five employees. Apparently, the publisher of the “Hyménomycètes”, Ch. Thomas was such a small company. Printing illustrations at that time required the preparation of lithograph plates. In addition, the illustrations of the “Hyménomycètes” were hand-coloured after print. So, as Gillet’s illustration of Eccilia rusticoides is the only known original material, it has to be selected as lectotype. It is also depicted here (Fig. 46A). To provide for a modern concept, based on a well-preserved specimen with colour photographs and an ITS-barcode sequence, a specimen is selected as an epitype that coincides well with the traditional concept of this species, as described among others in Kühner & Romagnesi (1953), and Noordeloos (1981, 1987, 1992, 2004), and as interpreted by the authors of this study. This concept matches the concept of E. graphitipes of Vila et al. (2014), which they treated as a distinct species based on an ITS sequence of the holotype. Regarding the original description of E. graphitipes, with nodulose heterodiametrical basidiospores, without encrusting pigment and the fruiting in spring, it appeared that this species might rather belong to sect. Erophila than to subgen. Omphaliopsis. This seemed to be supported by the fact that Ludwig compared his new species to E. farinasprellum, a species that we now know is a synonym of E. undulatosporum. The description of E. graphitipes by Vila et al. (2014) deviates in several characters from that of Ludwig and represents a typical member of the /Rusticoides clade with rather iso- to subisodiametrical spores and encrusting pigment. The pictures provided by Vila et al. (2014) illustrate a remarkable variability of this species, but the differences between their concept of E. graphitipes in comparison with the original one were not explained or discussed. A cross-contamination in the sequencing process or in the extreme case a mixed collection was considered by the present authors. However, the re-examination of the holotype revealed that E. graphitipes fits rather well into the concept of E. rusticoides. Each of the basidiomes of the holotype specimen were studied and the possibility of a mixed collection has been rejected. The deviation of the holotype of E. graphites from typical specimens of E. rusticoides, especially the lack of distinct encrusting pigment, can well be explained by the bad state of the basidiomata. The fact that also the infecting Aspergillus sp. is in a bad state of preservation, indicates that the specimen was already infected prior to drying. Nodulose basidiospores as depicted by Ludwig (2007) were not found in a healthy state, however, abortive, rather thin-walled spores without cell content were abundant and had sometimes similar shapes as those nodulose spores of the original description. The distinct proportion of broadly heterodiametrical spores is in general not contradicting the concept of E. rusticoides. Gillet included in his microscopical drawing isodiametrical to broadly heterodiametrical spores (Fig. 46A), Q-values of 1.0–1.5 were given for this species by Noordeloos (2004), and also the concept as revised here, based on sequenced specimens, includes a proportion of broadly heterodiametrical spores. Therefore, E. graphitipes has to be synonymised with E. rusticoides, and represents a specimen with an unusual fruiting date in spring of a species that is generally mainly found in late autumn. Like in many other species of Entoloma, cheilocystidia are present or absent in E. rusticoides, and must be considered of limited diagnostic value. The species treated as E. rusticoides by Vila et al. (2014) is a different species, which is only known from pronounced Mediterranean habitats. It is described as a new species, E. vilae, below.

Entoloma sericeoides (J.E. Lange) Noordel., Persoonia 10(4): 483. 1980. MB 113479. Figs 43, 47A–D.

Fig. 47.

A–D. Entoloma sericeoides (L0608318). A, B. Habit. C. Pileipellis. D. Basidiospores. E–H. Entoloma polyangulatum (WU-Myc 27147, holotype). E. Habit. F. Basidiospores. G. Pileipellis. H. Cheilocystidia. Photos: A by M.J.C. van der Vegte; B, C, D by G.M. Jansen; E by A. Hausknecht. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microstructures).

Basionym: Rhodophyllus sericeoides J.E. Lange, Fl. Agaric. Danic. 5: Vlll. 1940. MB 290538.

Synonym: Entoloma riedheimense Noordel. & Enderle, Z. Mykol. 61(2): 189. 1995. MB 545621.

Misapplied names: Entoloma costatum s. J. Lange, Romagnesi, Noordeloos; Entoloma defibulatum s. Vila et al.

Typus: Denmark, Fyn, Kværndrup, in forest (Fagus and Picea), 12 Jul. 1938, J.E. Lange (holotype C-F-110005); ITS sequence, GenBank PX412067.

Description (amended here): Basidiomata clitocyboid, often relatively stout, more rarely omphalinoid or collybioid. Pileus (10–)20–80 mm broad, convex then expanding to applanate, slightly depressed to umbilicate, with involute margin, with undulating marginal zone when old, hygrophanous, when moist dark grey brown, sepia, red brown, or blackish brown, not or indistinctly translucently striate, pallescent on drying to yellow brown or grey brown, smooth, glabrous, but becoming strongly radially fibrillose on drying. Lamellae crowded (L = 30–60, l = 1–5), broadly adnate with decurrent tooth or emarginate, arcuate to segmentiform, rarely subventricose, sometimes transvenose, pale brown then dark brown pink with entire or more or less serrate, concolourous edge. Stipe 25–90 × 3–10 mm, cylindrical or compressed, often tapering at base, grey brown or red brown, usually paler than pileus, coarsely fibrillose-striate lengthwise, solid then fistulose. Context concolourous with surface in cortex, inner parts white, fairly brittle. Smell indistinct. Taste mild to rancid. Basidiospores (120/6) (6.5–)7.0–9.5(–10.5) × (6.0–)7.0–8.0(–9.0) µm, on average 8.3–9.0 × 7.4–7.7 µm, Q = 1.00–1.30, Qav = 1.15–1.20, subisodiametrical, (4–)5–6-angled in side view. Basidia 20–36 × 8–14 µm, 4-, occasionally 2-spored, clamped. Lamella edge fertile or heterogeneous. Cheilocystidia usually absent, rarely scattered or abundant, then often in clusters, 60–75(–80) × 4–8(–9) µm, subcylindrical. Pileipellis a cutis of radially arranged, 2.5–8 µm wide hyphae, with numerous cylindrical to clavate, up to 15 µm wide terminal elements; subpellis made up of long, inflated elements, 90–180 × 4–20 µm. Hymenophoral and pileitrama regular, made up of long, cylindrical 5–25 µm wide hyphae. Pigment brown, intracellular, diffuse and granular, in pileipellis and upper pileitrama, in addition often distinctly encrusting. Clamp-connections absent (but present in the holotype of E. riedheimense).

Habitat and distribution: In groups in grasslands, both in semi-natural grasslands and in lawns, on dikes, etc., on clayey soil. Widespread in Northwestern Europe, and Spain (Vila et al. 2013, as E. defibulatum).

Additional material examined: Germany, Hessen, Frankfurt am Main, Campus Riedberge, Wissenschaftsgarten, in lawn, 19 Apr. 2018, H. Lotz-Winter, KaiR1196 (B 70 0105511); ibid., 4 Apr. 2019, H. Lotz-Winter, KaiR1364 (B 70 0105517); Baden-Württemberg, Schwäbische Alb, 18 Oct. 2019, F. Hampe, ACN6 (B 70 0105494); Bayern, Riedheim, in lawn, 13 Sep. 2002, M. Enderle (holotype of E. riedheimense, deposited in L; ITS sequence, GenBank PX412018); Frankfurt am Main, Niederursel, Kreuzerhohl, in semi-naturals grassland, 22 Nov. 2017, K. Reschke, KaiR1131 (B 70 0105509). The Netherlands, prov. Gelderland, Hennisdijk, Buren, in grassland on heavy clay, 9 Oct. 2020, G.M. Jansen & M.J.C. van der Vegte (L0608318).

Notes: The amended description now also acknowledges the occasional presence of encrusting pigment in the pileipellis of several collections studied, as well as forms with cheilocystidia. Small, more omphalinoid specimens (type of E. sericeoides) can be encountered besides the more typical robust sized E. costatum s. auct. form. The present concept represents Rhodophyllus costatus as interpreted by Lange (1937: 13, pl. 76F), and Romagnesi (1974), whose interpretations formed the basis of the description in Noordeloos (1981). It is a fairly characteristic species, with usually relatively stout basidiomata with a dark brown, umbilicate pileus, grey brown lamellae, relatively short, concolourous, fibrous stipe, odourless context, growing in groups in grasslands, often in company of the common E. sericeum. The small, rounded-isodiametrical spores, and clampless hyphae furthermore characterise this species, which instigated Romagnesi (In Romagnesi & Gilles 1979) to place it in a new section Clitopiloides, which accordingly was elevated to the rank of subgenus by Noordeloos (1992), and raised to generic rank in Largent (1994) as Clitopiloidea. In our ITS phylogeny, however, it fits well in subgen. Omphaliopsis. Entoloma sericeoides was described by Lange (1940) as a relatively small, dark brown, omphalinoid (eccilioid) species, with a relatively thin-fleshed, shortly translucently striate and umbilicate pileus, growing in a roadside in a forest with Fagus and Picea. As such, it appears to be a smaller, thin-fleshed version of E. costatum s. auct., which was confirmed by the ITS sequence of the holotype of E. sericeoides. Vila et al. (2014) erroneously identified E. sericeoides as E. defibulatum (GenBank JX454928.1). As a result, many records of E. defibulatum in recent publications, and in GenBank, actually refer to E. sericeoides. However, the true E. defibulatum is a synonym of E. fernandae, a very distant species in subgenus Nolanea (Reschke et al. 2022b, Noordeloos et al. 2022a).

Entoloma vilae Reschke, Noordel., O.V. Morozova, Manz & Dima, sp. nov. MB 860435. Fig. 46J.

Misapplied name: Entoloma rusticoides sensu Vila et al. (2014).

Etymology: The species is dedicated to the late Jordi Vila, a researcher of the mycobiota of Catalonia (Spain), who made an invaluable contribution to the study of Entoloma.

Typus: Croatia, Premantura, Kap Kamenjak, on soil in open thermophilous vegetation with Rosmarinus and Cistus, 1 Nov. 2016, C. Manz & A. Gminder (holotype B 70 0105501); ITS sequence, GenBank PX412072.

Description: Basidiomata omphalinoid. Pileus 10–12 mm wide, convex, deeply umbilicate, with involute margin, dark brown with blackish brown centre, distinctly translucently striate, soon opaque on drying, at centre somewhat felted-fibrillose, towards margin more or less virgate with darker and paler fibrils. Lamellae moderately distant (L = 10–20, l = 1–3), deeply decurrent, with concolourous, entire edge. Stipe 12–15 × 1–2 mm, cylindrical, pale to dark brown, sometimes darkening at apex, innately fibrillose, white felted at base. Context concolourous with sides. Smell indistinct, taste not noted. Basidiospores (20/1) 7.0–8.0 × 6.5–7.5 µm, on average 6.4 × 7.1 µm, Q = 1.00–1.20, Qav = 1.05, very rounded-angular. Basidia 4-spored, 33–40 × 9.5–11 µm, clampless. Lamella edge fertile, cystidia absent. Pileipellis a cutis with transitions to a trichoderm of cylindrical, 4–15 µm wide hyphae, with fine incrustations and pale intracellular pigment. Pileitrama regular. Stipitipellis a thin cutis of narrow hyphae. Caulocystida absent. Clamp-connections absent in all tissues.

Habitat and distribution: In short grazed, semi-natural, thermophilous grassland and Mediterranean shrubland with Olea, Pistacia and Thymus, also with Cistus and Rosmarinus, on calcareous soil. Known from Croatia and Spain.

Notes: As pointed out above, the concept of Entoloma rusticoides has been amended, and consequently E. rusticoides sensu Vila et al. (2014) needs to be described as a new species. It resembles E. rusticoides in many respects, but the ecology and distribution are Mediterranean. Three GenBank accessions (KJ001431, KJ001432, KJ001435) from Spain (Vila et al. 2014) also refer to E. vilae.

/Brunneoflocculosum subclade

The monotypic /Brunneoflocculosum subclade takes a long-branched, isolated position in the ITS phylogeny within the subgen. Omphaliopsis, sister to Entoloma punjabense from Pakistan without statistical support (Fig. 38). So far it had only been known from the type locality, but during our studies it appeared that the ITS is very similar to the type of E. asperum, described a few years later from Germany. Both type specimens were found in a xerophytic grassland in a calcareous area. Macroscopically both collections are rather similar with a dark brown felted-floccose pileus and polished stipe, but microscopically there are slight differences in spore size and the occurrence of cheilocystidia in the holotype of E. asperum. Since they belong to one well-supported clade phylogenetically, we treat these two taxa as one species for the time being.

Entoloma brunneoflocculosum Arnolds & Noordel., in Noordeloos, Entoloma s.l., Fungi Europaei vol. 5a: 982. 2004. MB 491533.

Synonym: Entoloma asperum E. Ludw., Hensel & M. Huth, Pilzkompendium 2(2): 484. 2007. MB 548578.

Typus: The Netherlands, prov. Limburg, Wittem, N.W. of Nijswiller, 30 Sep. 2001, E. Arnolds, Arnolds 01-116 (holotype L0607236, not sequenced), ibid., Arnolds 01-125 (paratype, deposited in L); ITS sequence, GenBank PX401863.

Description (amended here): Basidiomata mycenoid: Pileus 13–29 mm wide, obtusely conical to conico-convex, expanding to almost applanate with umbo, with crenulate margin, not hygrophanous, not translucently striate, centre dark brown, entirely felted-minutely squamulose, then furfuraceous-flocculose at centre, towards margin fibrillose-virgate, grey brown to yellow brown, exposing the paler context of the pileus between the fibrils. Lamellae moderately crowded (L = 21–23, l = 1–3), adnexed to emarginate, ventricose, white then flesh-coloured pink with concolourous, entire or paler, fimbriate edge. Stipe 15–30 × 1.5–3 mm, cylindrical, grey brown, darker blackish brown at base, apex pruinose, downwards polished. Context thin, pale grey brown in pileus, whitish in stipe. Smell and taste weak, fungoid. Basidiospores (40/2) (6.5–)7.0–10.0 × 6.0–8.0 µm, on average 8.5–9.2 × 7.0–7.5 µm, Q = 1.05–1.35, Qav = 1.20–1.25, subisodiametrical to heterodiametrical, 5–6-angled with pronounced angles. Basidia 23–30 × 10–12 µm, 4-, also sometimes 2-spored, in part thick-walled, clamped. Lamella edge fertile or heterogeneous with scattered, lageniform to utriform cheilocystidia, 30–55 × 4–12 µm. Hymenophoral trama regular, made up of relatively short, hyaline elements, 50–150(–165) × 3.5–30 µm. Pileipellis a cutis with trichodermal tufts of sub cylindrical to clavate, lageniform or fusiform terminal elements, 53–140 × 9–24 µm. Pigment pale to dark brown, diffusely intracellular. Clamp-connections present in hymenium and in trama, but infrequent.

Habitat and distribution: In poor, moss-rich xerophytic grasslands on loamy or calcareous soils. So far only known from The Netherlands and Germany.

Additional material examined: Germany, Sachsen-Anhalt, Thüringen, Müncheroda near Freyburg, Langer Berg, in xerophytic grassland on calcareous soil, 15 Aug. 2005, G. Hensel & M. Huth, Ludwig 2614 (holotype of E. asperum, M); ITS sequence, GenBank PX412013.

Notes: The type collections of Entoloma brunneoflocculosum and E. asperum were very similar in their ITS regions, so we consider them conspecific. This enabled us to get a better picture of the morphological variability within the species. The type of E. asperum has a larger percentage of 2-spored basidia, which explains the larger spore sizes observed. The presence of cystidia in E. asperum may indicate a degree of morphological differentiation, but in many Entoloma species presence or absence of cheilocystidia is a variable character and of limited diagnostic value. Illustrations of basidiomata and microscopic characters can be found in Noordeloos (2004) and Ludwig (2007).

/Claudopus clade – Entoloma subgen. Claudopus

Entoloma subgen. Claudopus (Gillet) Noordel., Persoonia 11: 147. 1981. MB 860550.

Basionym: Claudopus Gillet, Les Hyménomycètes ou Description de tous les Champignons qui Croissent en France: 426. 1876. MB 17311.

Synonyms: Entoloma subgen. Paraleptonia Romagn. ex Noordel. in Persoonia 11: 149. 1981. MB 90850.

Paraleptonia (Romagn. ex Noordel.) P.D. Orton, Mycologist 5(4): 174. 1991. MB 25374. – Type species: Entoloma neglectum (Lasch) Arnolds

Paraeccilia Largent, Entolomatoid fungi of the Western United States and Alaska: 368. 1994. MB 27619. – Type species: Eccilia sericeonitida P.D. Orton (= E. undatum).

Type species: Agaricus byssisedus Pers. = Entoloma byssisedum (Pers.) Donk

The /Claudopus clade coincides with subgen. Claudopus in the sense of He et al. (2019) and is an assemblage of small species with omphalinoid basidiomata or reduced, pleurotoid basidiomata, with an eccentric, lateral, or completely absent stipe. It contains species around the morphospecies E. byssisedum (pleurotoid) and E. undatum (omphalinoid). The species around E. rusticoides, i.e. the /Rusticoides clade included in the traditional concept of Entoloma subgen. Claudopus (Romagnesi 1974, Noordeloos 1981), form a distant clade (subgen. Omphaliopsis) and are excluded here from subgen. Claudopus (see also Vila et al. 2014, He et al. 2019). Since E. neglectum and related species are embedded within subgen. Claudopus, the (sub)genus Paraleptonia is considered a synonym of Claudopus. The same applies to Paraeccilia Largent, with its type E. sericeonitida, which is a synonym of E. undatum.

Species in subgen. Claudopus are often rather polymorphic and may vary from pleurotoid, with or without a strongly reduced lateral stipe (and then often identified as E. byssisedum), to omphalinoid with a well-developed, eccentric or central stipe (often identified as E. undatum). Considering this and the limited diagnostic value of micromorphological characters such as the size of basidiospores, presence or absence of cheilocystidia and pigmentation, it is often hard to distinguish morphological species within the subgenus. In addition, interpretation of classical names is not without problems, resulting in misapplications in literature. The ITS barcode differences may, however, support identification. Species of subgen. Claudopus have a world-wide distribution and, apart from our own sequences, additional data from various continents originating from recent publications (Largent et al. 2011a, Deng et al. 2015, He et al. 2015, 2019, Morozova et al. 2022), iNaturalist, and GenBank have been incorporated in our phylogenetic tree (Fig. 48). European names have often been applied to extra-European material, and therefore, in order to improve the taxonomy of subgen. Claudopus, we first attempt here to designate a lecto- an epitype for E. byssisedum, and a neotype for E. undatum. In addition, new sequences were obtained from recently described species, supplemented by many newly generated sequences from well-documented collections we could lay our hands on. As a result, we have a fairly large phylogenetic tree (Fig. 48) with numerous OTUs, and it is apparent that most of the European names used outside Europe seem to have been misapplied. Several of the clades representing unknown species are described here as new to science.

Fig. 48.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma subgen. Claudopus (= /Claudopus clade). ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Within subgen. Claudopus, traditionally a segregation was made between omphalinoid species (E. undatum type) and pleurotoid species (E. byssisedum type). In our study, we found that both of these morphotypes occur in several subclades of the tree. The top half of the present phylogenetic tree (the /Undatum clade (E. undatum–E. pseudonigellum) contains a couple of clades that often differ only in a few nucleotides, and includes both morphotypes mentioned above. There is little internal variation. The Entoloma undatum clade includes the holotype of E. undatoides. This means that some morphological variability must be accepted with regard to basidiomata colour and degree of zonation of the pileus. The next two subclades of the /Undatum clade contain species with pleurotoid basidiomata, generally identified as E. byssisedum sensu lato. The lower clade includes the epitype of E. byssisedum, the one above is described as the new species E. ostreatum. Within this last clade there is a slight segregation into European and Asian subclades. Entoloma korhonenii, originally described as a variety of E. undatum, appears to be a well-supported clade and a species in its own right. Other omphalinoid species sometimes confused with E. undatum, like E. lanicum, E. assimile, E. pseudonigellum and E. muscialpinum form well-supported clades in the lower parts of the tree. A rather well separated clade is formed by three extralimital species, including E. heae from China, and E. abortivum from North America. Entoloma pseudoparasiticum, with a pleurotoid appearance, is distant from E. byssisedum, and fixed here with an epitype. It also includes E. catalaense, and several collections identified as E. byssisedum var. microsporum. A number of small, pleurotoid species with pale basidiomata, often found hidden in vegetal debris or on rotten wood, is relatively poorly known. In the field they can be confused with Clitopilus or Crepidotus species. The subgenus includes E. jahnii and E. ollare, as well as a new species, E. nanoalbum which forms a well-supported clade with the rather similar E. pitereka from Australia. As is clear from the phylogeny, there are several (extralimital) lineages that represent potential new species, but they cannot be formally described because of the lack of sufficient morphological and ecological data.

Entoloma alliodorum Esteve-Rav., E. Horak & A. Ortega, Mycotaxon 86: 228. 2003. MB 372435.

Typus: Spain, Malaga, Yunquera, Sierra de las Nieves, Tajo de la Caina, on organic debris, among mosses (Homalothecium sericeum and Pleurochaete squarrosa) and lichens (Cladonia sp.) and very rotten wood of Abies pinsapo, Cistus albidus and Ulex baeticus, 1 Nov. 1994, L. Alcoba, F. Esteve Raventós, E. Horak & A. Ortega (holotype AH 16907, isotype L0607414); ITS sequence, GenBank PX412022.

Notes: Entoloma alliodorum is a rather isolated species in the phylogeny, only known from the type locality, and characterised by the white basidiomata and strong garlic smell. A full description can be found in Noordeloos (2004).

Entoloma assimile G.M. Jansen, Noordel., Biketova, L. Nagy & Dima, sp. nov. MB 860392. Fig. 49.

Fig. 49.

Entoloma assimile (L0608215, holotype). A–C. Habit. D. Basidiospores. Photos: G.M. Jansen. Scale bars: 1 cm (habit), 10 μm (spores)

Etymology: assimile (Lat.) – similar, referring to the likeness with E. undatum.

Typus: The Netherlands, prov. Zuid Holland, Oostvoorne, 25 Sep. 2015, G.M. Jansen, C149-2190 (holotype L0608215); ITS sequence, GenBank PX412024.

Description: Basidiomata omphalinoid, resembling E. undatum, but deeper umbilicate. Pileus about 10–25 mm wide, convex, deeply umbilicate to infundibuliform, warm reddish brown, deeply translucently striate, hygrophanous, subglabrous, with a few silvery, fibrillose patches, sometimes with concentric zones. Lamellae crowded (L = 30–46, l = 3–5), ascending and with decurrent tooth to deeply decurrent, pinkish brown then brown, almost like pileus, with concolourous, entire edge. Stipe 20–25 × 1–2 mm, cylindrical, flexuous, brown like pileus, glabrous, with basal mycelium. Context thin, brittle, brown. Smell and taste farinaceous. Basidiospores (40/2) 8.5–10.0 × 6.0–7.0 μm, on average 6.4 × 7.3 μm, Q = 1.30–1.60, Qav = 1.40–1.45, 6–7-angled with rather blunt angles. Basidia 23–40 × 8–11 μm, 4-spored, clamped. Lamella edge fertile, without cheilocystidia. Pileipellis a cutis of repent hyphae, 3–10 μm wide, with brown, intracellular and encrusting pigment. Pileitrama regular, made up of cylindrical to inflated hyphae, 5–20 μm wide, with brown, sometimes minutely incrusted walls. Stipitipellis a simple cutis of narrow, more or less encrusted, 5–15 μm wide hyphae; caulocystidia not observed. Clamp-connections present in all tissues.

Habitat and distribution: Gregarious in grassland on sandy soil in Atlantic coastal dunes (holotype) as well as continental steppe-like, semiarid grasslands and from an artificial island in the Venetian Lagoon. Known from The Netherlands, Italy and Hungary.

Additional material examined: Hungary, Bács-Kiskun, Kecskemét, L. Nagy, NL-3566 (SZMC); Bács-Kiskun, Tompa, on sandy soil, 22 Jun. 2018, A. Biketova, DB-2018-06-22-1 (ELTE). Italy, Veneto, Venezia, Cassa di Volnata, 30 Oct. 2004, E. Bizio & E. Campo (MCVE16854) (Osmundson et al. 2013).

Notes: Entoloma assimile is a phylogenetic species, morphologically rather similar to E. undatum, but phylogenetically distant, growing mainly in sandy pioneer vegetation, possibly with slightly smaller spores and more reddish tinges.

Entoloma byssisedum (Pers.) Donk, Bull. Bot. Gdns Buitenz. 18: 158. 1949. MB 297238. Fig. 50.

Fig. 50.

Entoloma byssisedum (A–B, D–G. LE 311782, epitype; C. Lectotype). A. Habit. B, D. Basidiospores. C. Lectotype plate C.H. Persoon. E. Basidium. F, G. Pileipellis. Photos: O. Morozova. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (all other figs).

Basionym: Agaricus byssisedus Pers., Icon. Desc. Fung. Min. Cognit. (Leipzig) 2: 56. 1800. MB 494576.

Typus: Persoon, 1800, Icones et descriptiones Fungorum minus cognitorum 2, tab. XIV, fig. 4 (lectotype, designated here, MBT 10028198). Russia, Tver Oblast, Staritsky District, vicinity of the Krutitsy Village, in Picea abies forest, on rotten Picea log, 13 Sep. 2015, O. Morozova, 76TV15 (epitype LE 311782, designated here, deposited at LE, MBT 10028199); ITS sequence, GenBank ON329327.

Description of the epitype: Basidiomata pleurotoid. Pileus 5–35 mm wide, plano-convex to applanate with irregularly undulating or lobed margin, slightly involute when young, sometimes concave, ovoid to reniform or irregular when seen from above, not hygrophanous or translucently striate, pale grey or greyish brown, entirely radially fibrillose, sometimes zonate, often densely covered with white arachnoid mycelium around the place of attachment to the substrate, turning into white rhizomorphs in the substrate. Lamellae moderately distant (L = 10–25, l = 1–5), to fairly crowded, thin, adnate to subdecurrent, ventricose, pale grey, then pinkish brown, with entire or slightly eroded, concolourous edge. Stipe (1–)3–5 × 0.5–3 mm, strongly reduced to almost indistinct, lateral, pale grey brown, concolourous with pileus, pruinose to distinctly silky-striate, with white mycelial strands at base, solid. Context thin, concolourous with surface. Smell and taste indistinct to slightly farinaceous. Basidiospores (140/8) 8.0–10.0(–10.8) × 5.5–7.0 μm, on average 9.0 × 6.3 µm, Q = 1.30–1.60, Qav = 1.40–1.45, heterodiametrical, 5–7-angled in side view. Basidia 4-spored, clamped. Lamella edge fertile or heterogeneous, cheilocystidia absent in epitype, but sometimes present in other collections studied. Pileipellis a cutis, sometimes with transitions to a trichoderm, made up of radially arranged, 2–9 µm wide, cylindrical or slightly inflated hyphae, with up to 12 µm wide, ascendant, inflated terminal elements; pigment membranal and additionally encrusting. Arachnoid covering consists of long, 5–8 µm broad, clamped hyphae. Oleiferous hyphae present in the pileitrama. Clamp-connections present, at least in hymenium.

Habitat and distribution: In groups on rotten wood, often on Picea logs, but also recorded on Alnus, Fagus and Betula. Widespread in boreal-temperate Europe, East to West Siberia.

Additional material examined: Finland, Savonia borealis, Kuopio, Puijo, Antikkalanrinne, herb-rich forest dominated by Picea abies, on stump, 9 Sep. 2011, K. Kokkonen, KK299/11, FIPUT626-14 (TUR194232). Norway, Buskerud, Ringerike, Ringkollen, moss-rich blueberry spruce forest, on decayed wood of spruce, 6 Sep. 2013, W.E. Johansen, B. Sunde & H.K. Johnsen (O-F-301245); Trøndelag, Sør-Trøndelag, Orkland, Grytdalen NR, Nordslættbekken, on decayed wood of spruce in mountain forest, 4 Sep. 2021, G. Gaarder, GG7945. Russia, Murmansk Oblast, Khibiny Mountains, Polar-Alpine Botanical Garden, on Alnus stump in a mixed forest, 4 Sep. 1974, L. Mikhailovsky, 1947-M-119 (LE F-9251); Novgorod Oblast, Valday District, Valdaysky National Park, near Shuya Village, in Pinus sylvestris-Picea abies forest, on decayed wood, 22 Aug. 2003, R. Halling, LE F-253830; Tver Oblast, Staritsky District, near Krutitsy Village, in Picea abies forest, on fallen log, 10 Sep. 2011, E. Pravdolyubova, LE F-311783; Komi Republic, Koygorodsky District, near the “Gran” touristic camp, left bank of the Mytets River, mixed forest, on a decaying stump, 16 Aug. 2022, M. Palamarchuk, SYKOf4200 (LE F-343742); Khanty-Mansiysk AO, Khanty-Mansiysk District, Shapsha Village, mixed predominantly coniferous forest, on soil among mixed litter, 3 Aug. 2015, N. Filippova, YSU-F-05690 (LE F-343733); Vologda Oblast, Kirillovsky District, Russian North National Park, Nylovitskoye forestry, 10 Sep. 2005, O. Shiryaeva, LE F-235265. Sweden, Jämtland, Skaerkan, rather old, selectively logged spruce birch forest, on a fallen Betula pubescens, 18 Aug. 2011, O. Miettinen, FIAPH196-12 (H7005545).

Notes: In the mycological tradition, Entoloma byssisedum has been interpreted as a small pleurotoid species with a pale grey brown, silky-fibrillose pileus, pinkish lamellae, and a reduced, whitish, pubescent stipe, growing on rotten wood, connected with white mycelial threads to the substrate (“byssisedus”). Our studies, however, have shown that there is more than one phylogenetic species answering these criteria, and therefore, we have chosen an epitype that fits well with the lectotype and original diagnosis. The photograph of the epitype shows several basidiomata connected to the rotten woody substrate with white mycelial threads that matches the original plate (lectotype). Noordeloos (1988) gave a description of E. byssisedum, based on very few collections, with rather large spores, 10–12 × 6.5–8 µm, apparently extending beyond the normal range for this species. As a consequence, a small-spored collection from Spain was described as E. byssisedum var. microsporum (Noordeloos 2004). Our current molecular study of numerous collections labelled E. byssisedum or E. byssisedum var. microsporum reveals that the epithets byssisedum and byssisedum var. microsporum appear in several non-related clades. In addition, we found that spore size may vary greatly in E. byssisedum but lies mostly within the range of 7.5–11 × 5.5–7.5 µm. We had to decide to choose one of these clades to represent the true E. byssisedum, in order to be able to clarify the nomenclature of the group. Accordingly, we have chosen a well-documented collection, nicely fitting the lectotype and protologue. Several collections labelled either E. byssisedum or E. byssisedum var. microsporum clustered in other clades, and belong to other species, including E. pseudoparasiticum, E. ollare, E. undatum and E. lanicum. Unfortunately, the holotype of E. byssisedum var. microsporum failed to yield a barcode sequence several times, so we cannot give a final opinion regarding the status of this variety. Some of the extralimital E. byssisedum or E. byssisedum var. microsporum identifications appear to be of different species that need to be studied more closely (e.g. in He et al. 2019). Entoloma byssisedum var. microsporum identified from China (He et al. 2019) belongs to E. pseudoparasiticum.

Entoloma lanicum (Romagn.) Noordel., Persoonia 11: 149. 1981. MB 112299. Fig. 51.

Fig. 51.

Entoloma lanicum (A, B, D. L4343886, epitype; C. LE F-343746). A–C. Habit. D. Basidiospores. Photos: A by E. Vis; B by G.M. Jansen; C by O. Morozova. Scale bars: 1 cm (habit), 10 μm (spores).

Basionym: Rhodophyllus lanicus Romagn., Revue Mycol. 1(3): 158. 1936. MB 268941.

Typus: France, Dept. Seine & Oise, Villecresnes, Sep. 1932, H. Romagnesi (lectotype in PC, designated by Noordeloos 1981). The Netherlands, prov. Zuid Holland, Voornes Duin, 64 200/435 866, 28 Aug. 2015, E. Vis (epitype L4343886, designated here, deposited at L, MBT 10028201); ITS sequence, GenBank PX412045.

Description: Basidiomata omphalinoid. Pileus 5–30 mm wide, convex to plano-convex, slightly depressed to umbilicate, or funnel-shaped, with involute then deflexed margin, not or slightly hygrophanous, not translucently striate, pale pinkish brown to medium brown with incarnate reflex or grey brown, slightly pallescent on drying, finely felted with loose, radially oriented fibrils, indistinctly to distinctly zonated, slightly pallescent on drying. Lamellae moderately distant (L = 20–26, l =1–3), adnate-decurrent, arcuate to subventricose, grey at first then pinkish brown to pinkish grey with concolourous, entire edge. Stipe 10–20 × 1–2 mm, central or slightly eccentric, cylindrical or tapering towards base, concolourous with pileus, with a white fibrillose-pruinose covering, with dense white mycelium at the base. Context thin, brittle, brown. Smell and taste indistinct or slightly farinaceous. Basidiospores (180/16) 7.0–10.0 × 5.5–7.0 µm, on average 7.8–8.5 × 5.5–6.7 µm, Q = 1.20–1.55, Qav = 1.40–1.50, heterodiametrical, (4–)5–9-angled in side view. Basidia 20–24 × 6–11 µm, 4-spored, clamped. Lamella edge fertile, cystidia absent. Pileipellis a cutis of radially arranged, cylindrical, 1.5–7 µm wide hyphae; pigment minutely encrusting Stipitipellis a cutis of cylindrical hyphae, 3–9 µm wide. Caulocystidia present, 20–40 × 5–12, subcylindrical, irregularly flexuous with rounded apex. Clamp-connections present in all tissues.

Habitat and distribution: Terrestrial or on woody litter (especially Fagus, Picea), also found on burnt wood, in calcareous forests, forest margins, etc., summer to autumn. Widespread in Europe, but not often recorded.

Additional material examined: Austria, Niederösterreich, Zwettl, Friedersbach, Schacher-Reuthofried, in mixed coniferous forest with scattered deciduous trees on mossy embankment, 11 Jul. 2009, A. Hausknecht (WU-Myc 0029784); Oberösterreich, Zell am Moos, Ruine Wildeneck, in forest margin, 5 Sep. 1999, A. Hausknecht (as E. neglectum, WU-Myc 19660). Czechia, Sidonie, Sidonie Nature Reserve, in Fagus forest, near the road together with Echinoderma asperum, 21. Aug. 2020, H. Ševčíková, HS-20-8-21-12 (BRM). Germany, Baden-Württemberg, Odenwald, near Ursenbach, L-trail, on soil between Fagus-litter, 13 Aug. 2023, K. Reschke, KaiR1689 (B 70 0105525); Bavaria, Paterzell, Paterzeller Eibenwald, moist Fagus-dominated forest with old Taxus baccata trees, on soil and attached to rotten wood pieces, 12 Sep. 2016, K. Reschke, KaiR139 (B 70 0105502); Steigerwald, near Ebrach, Fagus-dominated broad-leaved forest, on soil between leaf litter, 7 Aug. 2023, K. Reschke, KaiR1664 (B 70 0105524); Hessen, near Biedenkopf, Martinsbachtal, on rich soil under Fraxinus excelsior, 6 Aug. 2016, M. Theiss, ACN85 (B 70 0105500); Thüringen, Hasenthal, Pfmersbach, wayside beside brook, on probably calcareous soil, 15 Sep. 2023, A. Karich, IHI-23Ent04 (GLM-F139007). Norway, Akershus, Bærum, Dælivann, Godthåp, in calcareous Corylus-Fraxinus woodland, TEB 182-16 (O), DB6042 (ELTE); Akershus, Oppland, Lunner, Søndre Oppdalen, Mørkomdalen, Olstadskogen, timber track road in low herb Picea forest, 2 Sep. 2017, E. Bendiksen, EB 225/17 (O-F-254464), Mørkomdalen, Bredli SE, in track road (for timber) in low herb forest, 26 Aug. 2006, E. Bendiksen, EB 43/06 (O-F-253891); Telemark, Porsgrunn, Kolbjørn-Frierflogene NV, in calcareous Corylus-Fraxinus woodland, 9 Sep. 2015, T.E. Brandrud, TEB 216-15, RB-01 (O-F-254567); Telemark, Kragerø, Kammerfossåsen, rich Tilia forest margin, 4 Aug. 2016, T.E. Brandrud, TEB 98-16 (O-F-304881); Vestland, Sogn og Fjordane, Luster, Dalsdalen, Øygarden nord, on decaying Ulmus glabra log in broad-leaved forest, 6 Sep. 2018, G. Gaarder, GG7710/7726 (O-F-258245). Russia, Bryansk Oblast, Suzemsky District, “Bryansky forest” Nature Reserve, on rotten log in broad-leaved forest, 8 Aug. 2015, O. Morozova, 21BR15 (LE F-312716); Pskov Oblast, Pushkinogorsky District, near Mikhailovskoye Village, on soil on roadside in a mixed forest, 11 Sep. 2018, O. Morozova, 4PG18 (LE F-315955); ibid., 12PG18 (LE F-315960); Stavropolsky Krai, Pyatigorsk, Perkalsky Arboretum, on soil in mixed forest, 4 Aug. 2009, O. Morozova, 1TB09 (LE F-343724); Karachay-Cherkess Republic, Teberda State Biosphere Reserve, near Teberda, on Fagus log in Fagus orientalis-Abies nordmanniana forest, 6 Aug. 2009, O. Morozova, 23TB09 (LE F-343725); Sverdlovsk Oblast, vicinity of Krasnoufimsk, “Nizhneirginskaya oak grove” protected area, on soil in grassland, 27 Aug. 2024, O. Morozova, 178SV24 (LE F-343745); ibid., 186SV24 (LE F-343746).

Notes: Entoloma lanicum is similar to E. undatum, differing mainly by tomentose, often opaque, sometimes zonated, loosely fibrillose pileus, silvery fibrillose stipe, and slightly smaller spores. It differs also very slightly in ecology and prefers richer to calcareous forest sites, including rotten wood and wood chips, whereas E. undatum prefers grasslands, roadsides, or open spots in sandy dunes. Entoloma muscialpinum has an even more overlapping habitat and can sometimes co-occur with E. lanicum in rich forest (margins). The lectotype of E. lanicum, studied by Noordeloos (1981) could not be located in PC and might be lost. Therefore, an epitype is selected to fix this species with a recent collection and ITS barcode.

Entoloma nanoalbum Jalink, Noordel. & Dima, sp. nov. MB 860391. Fig. 52.

Fig. 52.

Entoloma nanoalbum (Jalink 9675, holotype). A–C. Habit. D. Basidiospores. Photos: L. Jalink. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores).

Etymology: nanus (Lat.) – dwarf, albus (Lat.) – white, referring to the tiny, white basidiomata.

Typus: The Netherlands, prov. Zuid Holland, Wassenaar, Meijendel, Kijfhoek East, on rotten wood of Fagus sylvatica, or on soil in broad-leaved forest, 22 Jul. 2019, L. Jalink, Jalink9675 (holotype, L); ITS sequence, GenBank PX412048.

Description: Basidiomata small collybioid to pleurotoid with reduced stipe. Pileus (1.5–)3–7 mm wide, applanate with deflexed margin, white, very thin (and opaque or slightly translucent), surface densely covered with woolly hairs. Lamellae very distant (L = 8–10, l = 0–1), sometimes forked and reduced, vein-like, white then pink from ripe spores. Stipe very short, central or lateral, white, slightly pubescent to felted. Context thin, brittle, white. Smell indistinct, taste not noted. Basidiospores (60/4) 7.5–10.0 × 5.8–7.9 μm, on average 9.1–9.3 × 6.8 μm, Q = 1.10–1.60, Qav =1.35–1.45, heterodiametrical, 5–6(–7)-angled in side view. Basidia 26–41 × 9–11 μm, 4-, rarely also 2-spored, clamped. Lamella edge fertile, cystidia absent. Pileipellis a loose cutis of cylindrical hyphae, 3–9 μm wide with abundant loose, semi-uplifted terminal elements, not pigmented. Clamp-connections present in all tissues.

Habitat and distribution: In groups on rotten wood of Fagus sylvatica, or on soil in broad-leaved forest. So far known in Europe from three localities in The Netherlands, and one in Germany (see note below).

Additional material examined: Germany, Chemnitz, Stärker Wald, on soil in a moist tyre track, 26 Aug. 2022, P. Welt, IHI-23Ent03 (GLM-F139801). The Netherlands, prov. Groningen, Trimunt, on soil in deciduous forest, 9 Aug. 2013, I. Somhorst, MY127 (L0607242); prov. Overijssel, Huize Dorth, Harfsen, NL 52.22358, 6.29453, on soil in deciduous forest, 11 Jul. 2020, M. Gotink (L0607607).

Notes: This species could well be mistaken for pleurotoid specimens of E. albotomentosum, but that species usually has much larger, 4–5-angled spores, no clamp-connections and is phylogenetically very distant belonging to subgenus Nolanea (Reschke et al. 2022b). Entoloma parasiticum differs by having isodiametrical spores. Interestingly, ITS sequences derived from soil samples (environmental DNA) from The Netherlands (ASV25 and ASV138) are identical to the holotype sequence, as well as to three sequences from the USA (GenBank KX195601, MK217433, OP101160). The matching soil-derived sequences indicate that this tiny and easily overlooked species apparently has a much wider geographic distribution.

Entoloma neglectum (Lasch) Arnolds, Biblioth. Mycol. 90: 339. 1982. amend. MB 112299. Fig. 53A–D.

Fig. 53.

A–D. Entoloma neglectum (A. O-F-300037, holotype of E. cremeoalbum; B–D. O-F-247973, neotype). A, B. Habit. C. Basidiospores. D. Pileipellis. E–G. Entoloma cettoi (WU 11500, holotype). E. Habit. F. Basidiospores. G. Cheilocystidia. Photos: A by J.B. Jordal; B. by T.E. Brandrud; E from A. Hausknecht. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (all other figs).

Basionym: Agaricus neglectus Lasch, Linnaea 3: 401. 1828. MB 372191.

Synonym: Entoloma cremeoalbum J.B. Jordal & Noordel., Öst. Z. Pilzk. 19: 127. 2010. MB 519096.

Typus: Holotype not existing. Norway, Akershus, Oppland, Lunner, Rønningsåsen NV, Bestemorsmyra, calcareous fen/mire, 3 Aug. 2014, T.E. Brandrud, TEB 52-14 (neotype O-F-247973, designated here, deposited at O, MBT 10028202); ITS sequence, GenBank PX412049.

Description (amended here): Basidiomata omphalinoid. Pileus 5–40 mm wide, plano-convex with umbilicate centre to infundibuliform, with involute or inflexed margin, often with irregularly lobed margin when old, not hygrophanous nor translucently striate, opaque, whitish to beige or very pale cream, flesh-coloured or pale brownish-isabella, entirely finely fibrillose-tomentose, sometimes aeriferous zonated, dull. Lamellae moderately distant to distant (L = 15–36, l = 1–3–7), broadly adnate to decurrent, sometimes forked, arcuate to segmentiform, up to 4.5 mm broad, sometimes thickish, white then pink with an entire to minutely serrate, concolourous edge. Stipe 10–30 × 1.5–2.5(–3) mm, often distinctly shorter than the diameter of the pileus, cylindrical or compressed, sometimes with somewhat swollen to bulbous base, white or hyaline, sometimes with grey or yellow tinge, usually with white arachnoid, fibrillose covering or white tomentose. Context thin, hyaline. Smell strongly farinaceous. Taste rancid farinaceous. Basidiospores in 4-spored forms (90/6) 9.0–13.0 × 6.0–10 µm, on average 10.5–12.0 × 7.5–9.0 µm, Q = 1.20–1.50, Qav = 1.30–1.35, heterodiametrical, 5–7-angled in side view; in 2-spored forms (40/3) 12.0–17.0(–18.5) × 7.5–10.0 µm on average 14.5–16.5 × 8.5–9.8 µm, Q = 1.40–2.20, Qav = 1.60–1.70, heterodiametrical, nodulose-angular, 6–10-angled in side view. Basidia 19–35 × 8–12 µm, 2- or 4-spored, clamped. Lamella edge fertile or heterogeneous, rarely entirely sterile with cheilocystidia, 20–75 × 8–25 µm, cylindrical-capitate to tibiiform or lageniform, thin-walled. Hymenophoral trama regular, made up of cylindrical elements, 80–160 × 7–35 µm. Pileipellis a cutis with transitions to a trichoderm, made up of 4–17 µm wide, inflated terminal elements, pigment intracellular, often almost invisible, in addition sometimes minutely encrusting. Pileitrama regular, made up of more than 200 × 5–30 µm wide, inflated elements, with abundant brilliant granules. Caulocystidia at apex scarce to abundant, 20–70 × 3–14 µm, cylindrical to capitate. Clamp-connections scattered to abundant.

Habitat and distribution: Gregarious in poorly managed, semi-natural grassland, meadows, roadsides, dune valleys, etc., preferably on (slightly) calcareous soil, also found in marshy vegetation with Sphagnum, including calcareous fens; up to the subalpine region in N Sweden; summer–autumn. Widespread all over Europe.

Additional material examined: Czechia, Český Šternberk, in artificial mossy grassplot (former meadow) on fluvial sediments, apparently distributed preferably on the interface between the lawn and the mineral soil dug up by moles, 4 Jun. 2016, J. Borovička (PRM 935993) – ITS sequence, GenBank PQ871413. Norway, Nordland, Bodø, Ausvika, calcareous, sandy, semi-natural grassland, 12 Aug. 2020, G. Gaarder & P. Alvereng, GG7805 (O-F-260855); Østfold, Fredrikstad, Sellebakk, among grass, sandy soil, 30 Jun. 2013, Ø. Weholt (O-F-303799); Telemark, Kragerø, Jomfruland landskapsvernområde, Saltstein, grazed, rich sandy dry meadow, shallow soil, 5 Jul. 2011, T.E. Brandrud, TEB 53-11 (O-F-248384); Trøndelag, Sør-Trøndelag, Oppdal, Aunsetra, in weakly calcareous semi-natural grassland grazed by sheep, 30 Aug. 2010, J.B. Jordal, P.G. Larsen (O-F-300037, holotype of E. cremeoalbum). Russia, Kamchatka Krai, near Esso Village, left bank of Uksichan River, on grassland soil, 7 Aug. 2005, O. Morozova, LE F-343729; Leningrad Oblast, Vyborgsky District, Berezovye Islands, Bolshoy Beryozovy Island, on soil on Calamagrostis epigejos grassland, O. Morozova, LE F-235368; Novgorod Oblast, Valdaysky District, vicinities of the Bolshoye Nasakino Village, on soil on grass-forb meadow on calcareous moraine, 20 Aug. 2003, O. Morozova, LE F-217933; Tyumen Oblast, Tobolsk, Kirov Street, on soil on grass turf, 2 Sep. 2016, B. Kapitonov, P9026251 (LE F-343730). Sweden, Jämtlands län, Östersund, Frösön, Summarhagen, horse pasture, 29 Aug 2018, K. Reschke, KaiR1274 (B 70 0105513); Lule Lappmark, Jokkmokk Padjelanta NP, Arranoajvve, 11 Aug. 2016, G. Gulden, GG160811 (GB-0207763); Lule lappmark, Jokkmokk Padjelanta NP, Ajajaure, 16 Aug. 2016, G. Gulden, GG160816 (GB-0207764); Norrbotten, Arjeplog, Vuoggatjålme SV, 11 Aug. 2018, J. Vauras, E. Larsson & J.B. Jordal, EL48-18 (GB-0207760; ITS sequence, GenBank PV018338).

Notes: Entoloma neglectum is a rather widespread species which occurs in a wide range of habitats. It has pale, rather small, somewhat short-set, omphalinoid basidiomata. Kokkonen (2015) compared several Finnish sequences with the holotype sequences of the two-spored E. cremeoalbum, and of E. cettoi and concluded that they probably can be considered synonymous. Our studies confirm the status of E. cremeoalbum, but the available accessions of E. cettoi (Fig. 53E–G) made us decide otherwise. Although there are only 3–4 differences in the ITS sequences compared to E. neglectum, the deviating morphology, and possibly also the thermophilous character of this southern species, made us decide to keep this species apart, also in view of the relatively small differences between many species in the whole Claudopus clade. Entoloma heterocystis, another morphologically close species, is probably very similar, differing mainly by the azonate pileus and lack of clamp-connections, but the holotype has not been successfully sequenced yet.

Entoloma ollare E. Ludw. & T. Rödig ex E. Ludw. & T. Rödig, Fungi Europaei 5a: 1139. 2004. MB 491792. Fig. 54.

Fig. 54.

Entoloma ollare (A, B, C, E. L4343849, epitype; D. LE F-343726). A, C, D. Habit. B. Basidiospores. E. Pileipellis. Photos: A, C by M.J.C. van der Vegte; B, E by G.M. Jansen; D by O. Morozova. Scale bars: 1 cm (habit), 10 μm (spores and pileipellis).

Synonym: Entoloma ollare E. Ludw. & T. Rödig, Z. Mykol. 58(2): 193. 1992. MB 358406, nom. inval., Madrid, Art. 40.3.

Typus: Germany, Berlin, Schöneberg, on compost in flower pot, 16 Dec. 1986, T. Rödig (holotype L0607186 – in poor condition, isotype in M). The Netherlands, prov. Gelderland, Rheden, Heiderust, 17 Oct. 2021, unpaved, sandy path with mosses in a graveyard, M.J.C. van der Vegte (epitype L4343849, designated here, deposited at L, MBT 10028203); ITS sequence, GenBank PX412052.

Description: Basidiomata minute, pleurotoid. Pileus 2.5–10 mm wide, convex, expanding with depressed centre to infundibuliform, with slightly involute margin, indistinctly hygrophanous, when young only slightly translucently striate and covered with a white bloom or arachnoid layer of silvery fibrils, glabrescent with age and then more distinctly translucently striate, first pale grey then pale cream-coloured. Lamellae adnate to slightly decurrent (L = 20–30, l = 1–3), subdistant, thickish, white then pink. Stipe 1–4 × 1 mm, central to eccentric, attenuated towards base, curved, concolourous with pileus, finely tomentose. Context very thin. Smell and taste indistinct or farinaceous. Basidiospores (60/4) 8.5–13.5 × 6.0–9.0 µm, on average 10.5–11.7 × 7.5–7.8 µm, Q = 1.20–1.90, Qav = 1.40–1.60, narrowly heterodiametrical with up to 7(–8), rather blunt angles. Basidia 20–40 × 6–12 µm, 4-, rarely also 2-spored, clampless. Lamella edge fertile. Cystidia absent. Pileipellis a trichoderm of septate, 3–15 µm wide hyphae with both minutely encrusting and pale brown, intracellular pigment. Clamp-connections absent.

Habitat and distribution: On compost in flowerpots indoors (holotype; Germany; epitype, Norway); terrestrial on bare soil with some liverworts, indoors, or on calcareous shallow-soil grassland or sandy soil in grasslands. Apparently widespread in Europe (but partly in glasshouses), and east to West Siberia.

Additional material examined: Denmark, Hejrede SØ (Biowide 120), on soil in fertilized grassland, 25 Sep. 2015, T. Læssøe & T. Smidth, DMS-718845 (C). Germany, Brandenburg, Hutelandschaft Altranft, base rich, semiarid grassland, 21 Oct. 2023, A. Karich & R. Ullrich (GLM-F139797). Norway, Telemark, Porsgrunn, Skjelsvika, in open calcareous, shallow soil grassland, 10 Oct. 2013, T. Læssøe & A. Molia, AM-248d-2013 (O-F-21916); Trøndelag, Sør-Trøndelag, Ørland, Tollefsvika, 16 Jun. 2019, in flower pot in glasshouse, K. Mandal & Ø. Weholt, KM-7-19. Russia, Khanty-Mansiyskiy autonomous okrug, 22.5 km E from Khanty-Mansiysk, in grassland, 20 Aug. 2010, O. Morozova, 46KH10 (LE F-343726).

Notes: Unfortunately, the holotype in Leiden as well as the isotype material deposited in Munich could not be sequenced, although attempts were made both with Sanger and NGS methods. Therefore, an epitype was selected (also from a flowerpot), and the description was amended. Despite the specific epithet, this species can be found both indoors and outdoors, in (often fertilized) grasslands. Entoloma exiguum, another pleurotoid species, differs from E. ollare by the slightly smaller spores, absence of incrustations in the pileipellis, and clamped hyphae. The holotype of E. exiguum has not been sequenced yet.

Entoloma ostreatum O.V. Morozova, Noordel., Reschke, Dima & E. Malysheva, sp. nov. MB 860390. Fig. 55.

Fig. 55.

Entoloma ostreatum (A, C–I. LE F-343741, holotype; B. LE F-343740). A, B. Habit. C, G. Basidiospores. D, F. Basidia. E. Cheilocystidia. H. Lamellae edge. I. Pileipellis. Photos: O. Morozova. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (all other figs).

Etymology: ostrea (Lat.) – oyster, referring to the pleurotoid habit of the basidiomata.

Typus: Russia, Primorsky Krai, Sikhote-Alin Nature Reserve, cordon Maisa, right bank of the Maisa River, mixed forest including Pinus koraiensis, Abies nephrolepis, Tilia amurensis, Acer mono, Quercus mongolica, on fallen log of a broad-leaved tree, 26 Aug. 2013, O. Morozova (holotype LE F-343741); ITS sequence, GenBank PX412054.

Description: Basidiomata pleurotoid. Pileus 5–35 mm wide, plano-convex to applanate, flat or uplifted, with at first incurved, then straight, sometimes crenulate margin, ovoid to reniform, shell-shaped or irregular in outline, not or only slightly hygrophanous, not translucently striate, pale grey or greyish brown, sometimes radially zonate, entirely radially fibrillose, with white arachnoid mycelium around the place of attachment to the substrate. Lamellae moderately crowded (L = 10–20, l = 3–7), thin, adnate to adnexed, ventricose, pale grey, then pinkish brown, with entire or slightly eroded, concolourous edge. Stipe (1–)3–10 × 0.5–3 mm, strongly reduced, eccentric or lateral, pale grey brown, concolourous with pileus, pruinose, sometimes with white, mycelial strands at base. Context concolourous with surface. Smell and taste farinaceous or not. Basidiospores (120/6) (7.8–)8.3–10.2(–11.0) × (5.5–)5.8–6.9(–7.2) μm, on average 9.2 × 6.5 µm, Q = 1.30–1.60(–1.70), Qav = 1.40–1.45, heterodiametrical, 4–7-angled in side view. Basidia 4-spored, clamped. Lamella edge fertile or heterogeneous, cheilocystidia cylindrical, flexuose, lageniform or irregular, if present. Pileipellis a cutis with transitions to a trichoderm, made up of radially arranged, 2–9 µm wide, cylindrical or slightly inflated hyphae, with 6–15 µm wide, ascendant, inflated or sometimes capitate, terminal elements, pigment membranal and additionally encrusting in some hyphae. Arachnoid covering consisting of 5–8 µm broad, clamped hyphae. Oleiferous hyphae present in the pileitrama. Clamp-connections present.

Habitat and distribution: In groups on rotten wood of broad-leaved trees. In Mediterranean to subalpine Europe and North Asia/Russian Far East.

Additional material examined: Austria, Oberösterreich, Kirchdorf an der Krems, NP Nördliche Kalkalpen, Rosenau am Hengstpaß, Krumme Steyrling-Tal, Blöttenbach-Tal, Blumauer Alm, xerophytic grassland, 16 Sep. 2016, I. Krisai-Greilhuber (WU-Myc 37815); ibid., 16 Sep. 2016, I. Krisai-Greilhuber (WU-Myc 30737). Croatia, Cap Kamenjak, near Premantura, 15 Nov. 2017, on bark of unidentified log, A. Gminder, KaiR1108 (B 70 0105508). Russia, Samara Oblast, Zhyguli Nature Reserve, in Tilia cordata forest, on dead wood, 21 Aug. 1990, A.I. Ivanov (LE F-18639); Karachaevo-Cherkesia Republic, Teberda Nature Reserve, near Teberda town, mixed forest, on dead wood, 15 Aug. 2009, E. Malysheva, LE F-343685; Primorsky Krai, Kedrovaya Pad Nature Reserve, near the Drovyanoi stream, mixed forest, on fallen log of a broad-leaved tree, 20 Aug. 2005, O. Morozova, LE F-253823; ibid., Sikhote-Alin Nature Reserve, cordon Blagodatnoye, bank of the Sukhoy stream, mixed forest including Pinus koraiensis, Quercus mongolica, on fallen log of a broad-leaved tree, 16 Aug. 2013, O. Morozova, LE F-343740.

Notes: Entoloma ostreatum resembles E. byssisedum in many respects and can best be distinguished with the help of an ITS barcode. Both species grow on decayed wood, not on the ground. Because some of the collections studied had well developed cheilocystidia, it was suggested that this species could represent E. depluens in the sense of Orton (1960). For various reasons we are not inclined to apply the name E. depluens for the present clade. The epithet depluens goes back to Batsch (1786) and has been sanctioned by Fries (1821). It described a small, pleurotoid Entoloma with a thin, pale, hairy cap, reddish lamellae and a reduced white stipe, growing among mosses on soil. In literature, E. depluens has been variously interpreted. Entoloma depluens sensu Bresadola (1929) depicts a greyish form, growing on soil, that has been interpreted as E. byssisedum, e.g. in Kühner & Romagnesi (1953). Cooke (1884: pl. 371) depicts a small whitish, stipitate Claudopus on wood and saw dust that Orton (1960) considered E. parasiticum. Orton (1960) published a more detailed description of a pinkish grey Claudopus, growing on soil, as E. depluens, differing from his concept of E. byssisedum mainly in the slightly larger spores, and presence of cylindrical cheilocystidia. The colour of the basidiomata he considered of minor value, since Orton states that both species are grey. Noordeloos (1982) described E. depluens from Denmark, which fits quite well with the description of Orton, growing on rotten Fagus wood, however. Unfortunately, we do not have sequence data of both Orton’s and Noordeloos’s material. The spore size given by Orton and Noordeloos for E. depluens fits rather well in the range given here for E. byssisedum, and, furthermore, cheilocystidia are present or absent in both E. byssisedum, and E. ostreatum. And as for the ecology, E. ostreatum and E. byssisedum grow on wood, whereas E. depluens is supposed to grow on the soil. So, in conclusion, we think E. ostreatum is not in agreement with the current concept of E. depluens. The question remains whether a true E. depluens exists. In our tree, the name E. depluens turns up also in the /pseudoparasiticum clade, a species with a different ecology, growing on decayed fungi, soil, and vegetal debris.

Entoloma pseudonigellum E. Ludw. & Noordel., Pilzkompendium 2: 299. 2007. MB 548553. Fig. 56.

Fig. 56.

Entoloma pseudonigellum (A. FP-2014-10-26; B. DB-2022-12-03-2; C–E. NL-2615). A, B. Habit. C, D. Basidiospores. E. Cheilocystidia. Photos: A by P. Finy; B by R. Molnár; C by L. Nagy. Drawings by L. Nagy. Scale bars: 1 cm (habit), 10 μm (all other figs).

Typus: Hungary, Bács-Kiskun, Kunbaracs, Ősborókás, on sandy soil near Pinus and Quercus, 10 Oct. 2004, E. Ludwig, 2526 (holotype, M); ITS sequence, GenBank PX412060.

Description (amended here): Basidiomata omphalinoid. Pileus 10–35 mm wide, hemispherical then convex, finally infundibuliform, with umbilicate centre, margin slightly enrolled when young, then deflexed or straight, not hygrophanous or translucently striate, black to greyish black, blackish brown when young then dark sepia brown to horn brown, greyish brown when old, radially fibrillose to very finely adpressed squamulose when young, becoming smooth with age and when exposed. Lamellae relatively distant (L = 20–30, l = 2–5), variably inserted, from adnate to decurrent, arcuate, 1–3 mm broad, dark grey brown or horn brown like the pileus, then tinged pink, with concolourous, entire edge. Stipe 10–50 × 1–2.5 mm, cylindrical, concolourous or paler than pileus, glabrous, shiny, slightly innately fibrillose lengthwise, dull. Context thin, brittle, brown. Smell indistinct or somewhat farinaceous, like mown grass. Basidiospores (40/3) 7.0–12.5 × 6.0–7.5 μm, on average 9.5–11.0 × 6.5–7.0 µm, Q = 1.20–1.90, Qav = 1.40–1.45, heterodiametrical, with 6–9 weak angles, a rather large number of deformed spores usually present, up to 15 × 7–8 µm. Lamella edge heterogeneous. Cheilo- and pleurocystidia usually present, scattered among the basidia, clavate to globose to sphaeropedunculate, 30–38 × 15–22 µm, thin-walled and easily collapsing. Hymenophoral and pileitrama regular to irregular, made up of cylindrical hyphae, with elements 70–190 × 5–13 µm. Pileipellis a cutis with transitions to a trichoderm, made up of cylindrical to inflated, 5–22 µm wide hyphae; pigment coarsely encrusting and in addition intracellular, brown. Stipitipellis a cutis of narrow hyphae. Caulocystidia absent. Clamp-connections present.

Habitat and distribution: In sandy soils including dunes, often near Populus, Juniperus and Crataegus. According to our observation and the publication of Nagy & Gorliczai (2007) the species is rather frequent in the steppe areas of central Hungary. However, based on ITS sequence data in GenBank (OR771770, PV056348), this species also occurs in California, USA, where it was found in two different counties (El Dorado and Siskiyou, see https://www.inaturalist.org/observations/168337577 and https://www.inaturalist.org/observations/255804247, respectively).

Additional material examined: Hungary, Bács-Kiskun, Kecskemét, on sandy steppe, L. Nagy, NL-2615 (SZMC), ibid., L. Nagy, NL-3560 (SZMC); Bócsa, on sandy soil, near Juniperus and Populus, 3 Dec. 2022, Re. Molnár, DB-2022-12-03-2 (ELTE); Fülöpháza, on sandy steppe, among mosses, 19 Apr. 2023, K.E. Császárné, CSEK-2023-04-19-1 (ELTE); Pest, Alsónémedi, at margin of a sandy pasture, 26 Oct. 2014, P. Finy, FP-2014-10-26 (ELTE).

Notes: Entoloma pseudonigellum is a remarkable species close to E. undatum from which it differs by the very dark, finely squamulose pileus and presence of cheilo- and pleurocystidia. The notable disjunct distribution of the species between Central Hungary and California, USA is not yet fully understood.

Entoloma pseudoparasiticum Noordel., Entoloma s.l., Fungi Europaei 5: 610. 1992. MB 361990. Fig. 57.

Fig. 57.

Entoloma pseudoparasiticum (A, D–G. LE F-312345, epitype; B. LE F-343744; C. LE F-344117). A–C. Habit. D, F. Basidiospores. E. Basidium. G. Pileipellis. Photos: A by K. Potapov; B, C, F, G by O. Morozova. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit) 10 μm (all other figs).

Synonym: Entoloma catalaense Noordel. & Contu in Noordeloos, Entoloma s.l., Fungi Europaei vol. 5 (Saronno) 5a: 1146. 2004. MB 491544.

Typus: Sweden, Uppland, Börstil, Tusko, 29 Aug. 1953, E. Almkvist (holotype UPS F-738326, not sequenced). Russia, Tatarstan Republiс, Zelenodolsky District, Ilyinskoye Village, Aiminskoye Forestry, Picea abies-Pinus sylvestris forest, on basidiomes of Cantharellus cibarius, 26 Aug. 2015, O. Safiullina & K. Potapov (epitype LE F-312345, designated here, deposited at LE, MBT 10028200); ITS sequence, GenBank PX412061.

Description: Basidiomata pleurotoid. Pileus 5–25 mm wide, plano-convex to applanate with irregularly undulating or lobed margin, slightly involute when young, round, ovoid to reniform, shell-shaped or irregular seen from above, not or only slightly hygrophanous, not translucently striate or, when moist, at margin only, pale grey or greyish brown, entirely radially fibrillose, often densely covered with white arachnoid tomentum. Lamellae moderately distant to fairly crowded (L = 10–25, l = 1–5), adnexed, adnate to decurrent, ventricose, pale grey, then pinkish brown, with entire or slightly eroded, concolourous edge. Stipe 3–15 × 0.5–3 mm, strongly reduced, eccentric or lateral, sometimes central, pale grey brown, concolourous with pileus, pruinose to distinctly silky-striate, with white mycelial covering at base, turning into white rhizomorphs at the substrate. Context concolourous with surface. Smell indistinct or fishy-rancid; taste not reported. Basidiospores (200/12) 8.0–10.4 × 5.5–7.0 μm, on average 9.3–9.5 × 6.1–6.3 µm, Q = 1.20–1.60, Qav = 1.30–1.40, heterodiametrical, 5–7-angled in side view. Basidia 26–43 × 9–12.5 µm, 4-spored, clamped. Lamella edge fertile, cystidia absent. Pileipellis a cutis with transitions to a trichoderm, made up of radially arranged, 2–6 µm wide, cylindrical or slightly inflated hyphae, with up to 10 µm wide, ascendant, inflated, terminal elements; pigment pale, intracellular and membranal. Oleiferous hyphae present in the pileitrama. Clamp-connections present at least in hymenium.

Habitat and distribution: In groups on basidiomata of Cantharellus and Craterellus spp., on rotten wood or on debris and soil. Rare, but widespread in Europe east to the Ural Mountains, recorded, and ITS verified also from the Russian Far East, China and North America.

Additional material examined: Finland, Regio aboensis, Koski, Hongisto, 18 Sep. 2004, M.-L. Heinonen & P. Heinonen, FIPUT514-14 (TUR172876); ibid., 15 Oct. 2011, M.-L. Heinonen & P. Heinonen, FIPUT643-14 (TUR196375); Halikko, Vuorentaka, Vaisakko, on Craterellus cornucopioides, 7 Sep. 1988, A. Puolasmaa, FIPUT428-14 (TUR095156); Lemu, Nyynaeinen, fairly rich forest dominated by Quercus robur, on Cantharellus cibarius, 6 Sep. 1993, L. Lindgren, FIPUT433-14 (TUR110539); Regio kuusamoensis, Kuusamo, Oulanka natural park, near Nurmisaarenrinne, lower course of the dried brook of Tulilammenpuro, 3 Sep. 2007, J. Vauras & K. Kokkonen, FIPUT575-14 (TUR179915). Hungary, Veszprém, Bakony Mts, Fenyőfő, in road boarder, on sandy calcareous Pinus sylvestris forest, on dead plant debris, 17 Oct. 2022, B. Dima, V. Papp & B. Palla, DB-2022-10-17-4 (ELTE). Italy, Sardinia, prov. Sassari, Calangianus, Catala, among lichens and mosses on roadside, 12 Sep. 2003, M. Contu, G. Consiglio & L. Perrone (L0819832, holotype of E. catalaense; ITS sequence, GenBank PX412028). Norway, Nordland, Grane, Holmvassdalen NR, calcareous tall herb spruce forest, on remains of tall herbs, 5 Aug. 2011, S. Eidissen & J. Lorås, JL 204-11 (O-F-249954); Troms, Storfjord, Helligskogen, on wood of Betula, 17 Aug. 1992, E. Johannesen (TROM-F-94). Russia, Murmansk Oblast, near Kandalaksha town, coast of the Kandalaksha Gulf, mixed Pinus sylvestris-Picea obovata forest, on soil, 24 Aug. 2023, O. Morozova, NVP1033 (LE F-344117); Moscow Oblast, border of the Stupino and Serpukhov Districts, in mixed forest, on Cantharellus cibarius, 13 Aug. 2019, T. Bekker, LE F-343686; Tula Oblast, Belyovsky District, near the former Village Khutora, on a rotten stump in Picea forest, 1 Oct. 2003, T. Svetasheva, LE F-235003; Sverdlovskaya Oblast, Prigorodny District, Visimsky Nature Reserve, on soil in Betula forest, 26 Aug. 1999, L.V. Marina, LE F-258106; Kamchatka Krai, Bystrinsky District, near Esso Village, right bank of the Bystraya River, on a rotten stump in Populus-Salix forest, 11 Aug. 2005, O. Morozova, 156KA05 (LE F-343744).

Notes: Entoloma pseudoparasiticum and E. parasiticum are found to grow on different species of Cantharellaceae. Entoloma pseudoparasiticum differs from E. parasiticum by the brown coloured pileus, and small, heterodiametrical spores. Furthermore, E. pseudoparasiticum is apparently not exclusively parasitic on fungi but also occurs on soil or very decayed wood or other plant debris. Our results show that the type specimen of E. catalaense belongs to the same clade and represents a later synonym. Entoloma catalaense was considered to be characterised by its very strong, fishy-rancid smell, like that of Macrocystidia cucumis, but obviously this is not typical for the species, as this smell has not been noted for the majority of the known collections. Entoloma alliodorum differs by a differentiated pileipellis consisting of up to 15 µm broad elements, larger spores, and less frequent clamp-connections (Esteve-Raventós et al. 2003), and is phylogenetically distant. Entoloma pseudoparasiticum apparently has a very wide distribution, as it has also been recorded from China (He et al. 2019 and North America (e.g. iNat64301061), both as Entoloma byssisedum var. microsporum).

Entoloma undatum (Gillet) M.M. Moser, Kl. Krypt.-Fl. (Stuttgart) 2b/2: 211. 1978. MB 313840. Fig. 58.

Fig. 58.

Entoloma undatum (A. B 70 0105514, neotype; B. LE F-315976; C. LE F-343748; D. L0537412). A–C. Habit. D. Basidiospores. Photos: A by K. Reschke; B, C by O. Morozova. Drawing by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores).

Basionym: Clitopilus undatus Gillet, Les Hyménomycètes ou Description de tous les Champignons qui Croissent en France: 407. 1876. MB 241395.

Replaced synonym: Agaricus undatus Fr., Epicrisis Systematis Mycologici: 149. 1838. MB 461571, nom. illegit., non Agaricus undatus Berk. MB 239409.

Synonyms: Entoloma undatoides Arnolds, Ecol. Coenol. Macrofungi Grassl. Heathl. Drenthe, Netherlands 3: 352. 1983. MB 108868

Entoloma sericeonitidum (P.D. Orton) Arnolds, Ecol. Coenol. Macrofungi Grassl. Heathl. Drenthe, Netherlands 3: 350. 1983. MB 108867.

Excluded: Entoloma undatum f. longipes Noordel. Annls Univ. Turku., Ser. A II (Rep. Kevo subarct. Res. Stn 17) 66: 39. 1981. MB 118022 (= E. korhonenii).

Typus: Holotype not existing. Sweden, Jämtlands län, Östersund, Frösön, Summarhagen, 29 Aug. 2018, K. Reschke, KaiR1275 (neotype B 70 0105514, designated here, deposited at B, MBT 10028197); ITS sequence, GenBank OL338187.

Description (amended here): Basidiomata omphalinoid. Pileus 8–40 mm wide, convex to concave, usually deeply umbilicate, with slightly to distinctly involute margin when young, then straight or reflexed in old specimens, not distinctly hygrophanous, not translucently striate, dark grey brown, sometimes paler with age, or appearing pale grey brown from the aeriferous covering, densely radially fibrillose with adpressed to loosely attached silvery-greyish fibrils, often with one or more concentric zones, shiny, especially when dry. Lamellae fairly crowded (L = 20–35, l = 1–5), decurrent arcuate, grey or brown, then tinged pink, with an entire, concolourous edge. Stipe 10–30 × 1–4(–6) mm, cylindrical or compressed, sometimes broadened at base, pale brown to yellow brown paler than pileus, smooth or finely white pruinose in upper part. Context thin, concolourous with surface. Smell none or distinctly farinaceous. Taste none or farinaceous to rancid. Basidiospores (200/20) (7.0–)7.5–10.0 × 6.0–7.0 μm, on average 8.4–9.5 × 6.5–6.8 µm, Q = 1.20–1.65, Qav = 1.35–1.50, 6–8-angled in side view with weak, rounded angles. Basidia 20–32 × 9.5–14 µm, 4-spored, clamped. Lamella edge fertile. Cheilocystidia absent, rarely some scattered subcylindrical elements present, 25–60 × 3.5–8 µm. Pileipellis a cutis of radially arranged, cylindrical to clavate, terminal elements, up to 15 µm wide. Pigment yellow brown, membranal and encrusting the hyphae of pileipellis and pileitrama. Stipitipellis a cutis of cylindrical hyphae. Caulocystidia absent. Clamp-connections present in all tissues.

Habitat and distribution: Terrestrial, rarely on well decayed wood, in groups in grasslands, also on bare soil, often in pioneer vegetation on rather poor, sandy or gravelly soil, including tracks/road verges and inner sand-dunes or in rich, broad-leaved forests; summer to autumn. Widespread and common, Europe.

Additional material examined: Austria, Steiermark, Stainach-Pürgg, Wörschachwald, Spechtensee, 5 Sep. 2002, A. Hausknecht et al., WU-MYC 22285. Finland, Ostrobottnia ultima, Keminmaa, Vanha kirkko, 18 Sep. 2011, T. Kekki, FIPUT637-14 (TUR196105). Germany, Hessen, Darmstadt, near Pfungstadt, in sandy Pinus sylvestris forest on humus rich soil under shrubs, 4 Nov. 2022, K. Reschke, KaiR1610 (B); Rheinland-Pfalz, Bad Kreuznach, Schlossböckelheim, Heimberg, oligotroph grassland, 27 Oct. 2017, K. Reschke, KaiR998 (B 70 0105507). Hungary, Bács-Kiskun, Kecskemét, on sandy soil, L. Nagy, NL-0575 (SZMC). Norway, Nordland, Alstahaug, Tjøtta, semi-natural pasture, 30 Aug. 2020, J.B. Jordal, JBJ20-E47 (O-F-260838); ibid., 29 Aug. 2020, J.B. Jordal, JBJ20-E28 (O-F-260822); Oslo, Nordmarka, Finnerud, pasture, forest farm, well grazed by cattle and sheep, 27 Sep. 2016, E. Bendiksen, EB 180/16, (O-F-253869); Nordland, Evenes, Botn, birch forest, 16 Aug. 2005, Tromsø Soppforening (TROM-F-14005); Agder, Vest-Agder, Farsund, Hamrestranda, semi-natural pasture on sand, 24 Sep. 2012, J.B. Jordal (O-F-224771); Møre og Romsdal, Giske, Vigra, Molnes, calcareous semi-natural grassland, 27 Sep. 2022, J.B. Jordal, JB22-131 (O-F-259777); ibid., 30 Sep. 2004, J.B. Jordal (O-F-178025); Møre og Romsdal, Hustadvika, Farstadsanden, on sand in stable sand dune, 24 Sep. 2004, J.B. Jordal (O-F-178064); Akershus, Asker, Ormodden, calcareous Tilia-Corylus woodland, 12 Sep. 2019, B. Dima & E. Bendiksen, EB 105/19 (O-F-256899); Telemark, Porsgrunn, Skjelsvika, on open, calcareous, shallow soil, 20 Aug. 2013, A. Molia & T. Læssøe, AM-102p-2013 (O-F-21712). Russia, Komi Republic, Ust-Kulomsky District, Don Village, on soil on grassland, 26 Aug. 2008, M. Palamarchuk, SYKOf622 (LE F-343737); Altai Krai, Krasnoshchokovsky District, near Tigirek Village, Chainaya Mt, on soil in the Dasiphora fruticosa thickets, 12 Aug. 2016, I. Gorbunova, LE F-343735; Kamchatka Krai, vicinities of the Esso Village, left bank of the Uksichan River, on soil on roadside, 7 Aug. 2005, O.V. Morozova, LE F-343738; Perm Krai, Perm City, protected area “Chernyayevsky Forest”, on soil in secondary broad-leaved forest, 3 Sep. 2024, O. Morozova, A. Alexandrova & T. Svetasheva, 290SV24 (LE F-343748); Leningrad Oblast, Kirovski District, vicinity of the Turyshkino Village, on a piece of wood on the roadside, 2 Sep. 2004, O. Morozova, 6TU04 (LE F-343736); Novgorod Oblast, Valdaysky National Park, near Sokolovo Village, on soil on grassland, 24 Aug. 2003, O. Morozova, 03-08-252 (LE F-312417) (Morozova et al. 2018); Novosibirsk Oblast, Novosibirsk, Central Siberian Botanical Garden, 39 quarter, in oak and larch planting, 15 Aug. 2018, D. Ageev, Ageev272 (LE F-343734); Pskov Oblast, Pushkinogorsky District, between Mikhailovskoye and Savkino Villages, roadside in a mixed forest, 28 Aug. 2019, O. Morozova, 59aPG19 (LE F-315976); Samara Oblast, Stavropolsky District, Zhigulyovsky Biosphere Reserve, on rotten wood in Populus tremula forest, 12 Aug. 2003, E.F. Malysheva, LE F-227442; Sverdlovsk Oblast, Krasnoufimsk District, near the Emanzelga Village, “Emanzelga Mount” protected area, on soil in broad-leaved forest, 30 Aug. 2024, O. Legoshchina, 266SV24 (LE F-343747); ibid., on soil in birch forest, 30 Aug. 2024, O. Morozova, 258SV24 (LE F-343743). The Netherlands, Drenthe, Rolde, Eexterveld, mossy meadow close-cropped by sheep, 28 Oct. 1976, E. Arnolds, Arnolds 3702 (L0537412, holotype of E. undatoides; ITS sequence, GenBank PX401859).

Notes: Entoloma undatum is taken here in a rather broad sense, including odourless forms and those with a farinaceous smell, and those with distinctly zonate pileus or not, including E. undatoides. In order to decide which of the clades/OTUs represents the true E. undatum we chose this OTU because the macro- and micromorphology coincides with the widely accepted current concept as used for example in Kühner & Romagnesi (1953), Orton (1960), Noordeloos (1987, 1992). A specimen collected in Sweden is chosen as neotype owing to the fact that the species was first (illegitimately) described by Fries.

/Leptonia clade – subgen. Leptonia

Entoloma subgen. Leptonia (Fr.) Noordel. Persoonia 11: 146. 1981. MB 842393.

Basionym: Agaricus trib. Leptonia Fr., Syst. Mycol. (Lundae) 1: 10, 201. 1821. MB 700044.

Type species: Entoloma euchroum (Pers.) Donk

The /Leptonia clade coincides with subgenus Leptonia and has monographically been treated for Europe in Morozova et al. (2014a), and Noordeloos et al. (2022a). In Noordeloos et al. (2022a), section Lepidissima included a series of morphologically rather different species, viz. E. allochroum, E. callichroum, E. coelestinum, E. kruticianum, E. lepidissimum, E. percoelestinum and E. venustum. Ongoing research, however, demonstrated that these species actually belong to four different clades (Fig. 59). Section Lepidissima is now restricted to E. lepidissimum and E. kruticianum. Entoloma coelestinum and the related E. percoelestinum and the Asian E. tadungense, form a distinct clade of their own and can be accommodated in Entoloma sect. Lepidocybe. This necessitates the following new combination:

Fig. 59.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of Entoloma subgen. Leptonia (= /Leptonia clade). ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contain accession numbers, while for the newly generated sequences only voucher numbers are indicated. Countries of origin are indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma sect. Lepidocybe (Largent) O.V. Morozova, Noordel., Reschke & Dima, comb. nov. MB 860450.

Basionym: Leptonia sect. Lepidocybe Largent, Mycologia 66: 1017. 1974. MB 842274.

Type species: Entoloma coelestinum (Fr.) Hesler

The status of the remaining species (E. allochroum, E. callichroum and E. venustum) within sect. Lepidissima sensu lato remains uncertain for the time being.

Entoloma sect. Icterina (Konrad & Maubl.) Reschke, Noordel., O.V. Morozova & Dima, comb. nov. MB 860549

Basionym: Nolanea sect. Icterinae Konrad & Maubl., Icon. sel. Fungorum (fasc. 7): 210. 1932. MB 860547.

Synonym: Nolanea sect. Ameides Largent, Entolomatoid fungi of the Western United States and Alaska: 194. 1994. MB 538893. – Type species: Entoloma ameides (Berk. & Broome) Sacc.

Type species: Agaricus icterinus Fr. = Entoloma pleopodium (Bull.) Noordel.

Reschke et al. (2022b) combined Nolanea sect. Ameides into Entoloma and placed it in subg. Leptonia. However, they did not recognise that Nolanea sect. Icterinae was an older, valid name for this section. The ‘Icones selectae Fungorum’ were first published in 10 fascicles from 1925–1936. The ‘Entolomées’ were included in the 7th fascicle, published in 1932, so a Latin description was not required. It should be noted that Agaricus icterinus is a synonym of E. pleopodium.

Entoloma cobaltichroum O.V. Morozova, T.H.G. Pham & Reschke, nom. nov. MB 860447.

Replaced synonym: Entoloma dichroides O.V. Morozova & T.H.G. Pham, J. Fungi 9 (6, no. 621): 17. 2023. MB 848531, nom. illegit., Madrid, Art. 53.1, non Entoloma dichrooides (Romagn. & Gilles) Noordel. & Co-David, in Co-David et al., Persoonia 23: 167. 2009. MB 513604.

Etymology: Referring to the cobalt blue dye – the colour of the basidiomata.

Typus: Viet Nam, Dak Nong Province, Dak Glong District, Ta Dung National Park, northwest of the Ta Dung Mt, TK 1781, N11.923056, E 108.00194, 1000 m.a.s.l., on soil in evergreen broad-leaved forest with Parashorea chinensis, Rhodoleia championii, Fagaceae, Lauraceae, and Hypericaceae, 1 Jun. 2022, T.H.G. Pham (holotype LE F-343682; isotype HG09 in VRTC); ITS sequence, GenBank OQ779472.

Description: For original description see Morozova & Pham (2023).

Entoloma fraudans J.B. Jordal, Noordel., O.V. Morozova & Dima, sp. nov. MB 860421. Fig. 60.

Fig. 60.

Entoloma fraudans (O-F-261021, holotype). A, B. Habit. C, F. Basidiospores. D, G. Basidium. H. Cheilocystidia. I, J. Pileipellis. Photos: A, B by T.H. Hofton; F–H by G.M. Jansen. Drawings by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (spores and cheilocystidia).

Etymology: fraudans (Lat.) – cheating, i.e., posing as E. euchroum.

Typus: Norway, Vestland, Sogn & Fjordane, Luster, Mørkridsdalen, Bratten-Dalen, 112 m.a.s.l., in old, mixed broad-leaved forest with big Ulmus glabra, low herb-tall herb vegetation, on dead wood of Alnus incana, 9 Oct. 2021, T.H. Hofton, THH21159 (holotype O-F-261021); ITS sequence, GenBank PX412035.

Description: Basidiomata collybioid. Pileus 20–30 mm wide, conico-convex then convex, with involute margin, not hygrophanous or translucently striate, very dark purple brown then medium dark reddish brown with purple-blue tinges, particularly near margin, entirely minutely squamulose with dark brown grey, fibrillose, adpressed squamules, in mature specimens showing the slightly paler background colour of the context. Lamellae moderately distant (L = around 30, l = 3–7), adnate-emarginate, with small decurrent tooth, subventricose, bright purple-lilaceous, then pink-dusted with spores, with more or less entire, concolourous edge. Stipe 20–40 × 3–6 mm, cylindrical, dark purple–lilaceous then darker grey, coarsely fibrillose lengthwise, with abundant whitish mycelium at base. Context concolourous with surface. Smell indistinct, taste not noted. Basidiospores (60/4) 8.8–10.5(–11.5) × 6.2–7.6 μm, on average 9.6–10.0 × 7.0–7.2 μm, Q = 1.40–1.70, Qav = 1.50–1.58), heterodiametrical with 6–9 rather blunt angles in side view. Basidia 40–36 × 10–9.5 μm, 4-spored, narrowly clavate, clamped. Lamellae edge fertile or heterogeneous. Cheilocystidia 24–60.8 × 5.6–8.9 μm, scattered among basidia, cylindrical, narrowly clavate or lageniform, sometimes septate, thin-walled, hyaline. Pileipellis a trichoderm at centre, plagiotrichoderm towards the pileus margin, made up of cylindrical, septate hyphae with clavate or ovoid, 11–30 μm wide terminal elements, with brown (in KOH) intracellular, sometimes agglutinated pigment. Stipitipellis of long, 5–10 μm wide, septate hyphae, with slightly thick-walled, up to 200 μm long hairs with brown intracellular and sometimes incrusted pigment. Caulocystidia absent. Clamp-connections present in all tissues.

Habitat and distribution: So far only found in the fjord districts of Western Norway; on trunks of Ulmus glabra and Alnus incana, partly on very coarse, moss-covered trunks of very old trees.

Additional material examined: Norway, Møre & Romsdal, Molde, Eikesdalen, Under Rangåfjellet, in Corylus forest with Alnus incana and Galium odoratum, 25 Sep. 2009, W.E. Johansen (O-F-249678); Vestland, Luster, Mørkridsdalen, tall herb Ulmus glabra forest, 9 Oct. 2021, H.L. Jensen, HLJ21-01 (O); ibid., on dead wood of Ulmus glabra, 9 Oct. 2021, S. Khalsa, SK21-E01 (O); ibid., on dead lying Ulmus glabra trunk, 9 Oct. 2021, E. Kagge, EK21-E01 (O).

Notes: Entoloma fraudans is similar to E. euchroum, a species of subgen. Leptonia that is widespread in Europe on dead wood (mostly Alnus, but also Fagus, Quercus, Sorbus, Corylus, Acer, and Prunus) (Morozova et al. 2014a). The new species differs by the darker, pronounced squamulose pileus, coarsely fibrous stipe, and by having a concolourous lamella edge. Microscopically, it is distinguished by the hyaline, thin-walled and scattered cheilocystidia in contrast with the sterile edge in E. euchroum. In the phylogeny, its position is sister to E. lampropus which has similar cheilocystidia.

Entoloma lidbergii Noordel., Österr. Z. Pilzk. 3: 38. 1994. MB 362387. Fig. 61.

Fig. 61.

Entoloma lidbergii (LE F-234260). A. Habit. B, E. Basidiospores. C, G. Cheilocystidia. D, F. Basidia. H. Pileipellis. Photos: G.M. Jansen. Drawings: A by V. Malysheva; B, C, D by M.E. Noordeloos. Scale bars: 1 cm (habit), 10 μm (microscopic structures).

Typus: Sweden, Medelpad, Borgsjö, Julåsen, in a gravelly roadside, 25 Aug. 1986, M.E. Noordeloos, 86100 (holotype L0054018); ITS sequence, GenBank PX440387.

Description (amended here): Basidiomata collybioid. Pileus 4–10 mm wide, convex or conico-convex then applanate, with blunt centre or with small umbo, with straight or involute margin, hygrophanous, when moist translucently striate up to half of the radius, very pale pinkish brown or violaceous, paler towards margin, very finely squamulose all over, becoming paler, opaque, finely tomentose upon drying. Lamellae very distant (L = 10–16, l = 0–1), free to adnexed, ventricose, pink with an entire, concolourous edge. Stipe 12–30 × 0.5–1 mm, cylindrical, violaceous-pink, violaceous to dark bluish-violaceous, minutely striate with blue fibrils on the entire length, base white tomentose, but slowly turning yellow when bruised. Context very thin, concolourous with surface. Smell none. Taste not noted. Basidiospores (30/2) (8.2–)9.0–11.0 × (6.3–)7.0–8.0 μm, on average 9.5–9.7 × 7.1–7.3 μm, Q = 1.20–1.60, Qav = 1.30–1.35, rather regularly to slightly irregularly (4–)5–7-angled in side view. Basidia 16–40 × (7.0–)9.0–15.0 µm, 4-spored, clamped. Lamella edge heterogeneous. Cheilocystidia single or in clusters, 30–90 × 5.0–10.0 µm, often septate, irregularly coralloid. Hymenophoral trama regular, made up of inflated elements, up to 150 × 420 µm. Pileipellis a cutis with transitions to a trichoderm, made up of clavate terminal elements, 40–70 × 8–17 µm, with intracellular pigmentation. Stipitipellis a loose cutis of cylindrical hyphae. Caulocystidia absent. Clamp-connections present in all tissues.

Habitat and distribution: Solitary, terrestrial, on gravelly, slightly calcareous soil at a roadside in a boreal Picea forest with scattered Salix caprea (type) and temperate, rich Tilia forest (SW Russia along Volga). So far only known from the type locality in Sweden and one in Russia.

Additional material examined: Russia, Samara Oblast, Zhigulevsky Nature Reserve, vicinities of Bakhilova Polyana, Maloye Kamennoye Pole, on soil in Tilia cordata forest, 3 Jul. 2005, E. Malysheva (LE234260, as E. dichroum; ITS sequence, GenBank KC898442; mtSSU sequence, GenBank KC898487; nrLSU sequence, GenBank KC898528; Morozova et al. 2014a).

Notes: Entoloma lidbergii clearly belongs to subgen. Leptonia on account of its violaceous-blue, striate stipe and clamped hyphae. Also, the heterogeneous lamella edge with scattered, coralloid cheilocystidia is very typical for this group. It differs from all taxa in subgenus Leptonia by its very small size, and pale pinkish brown to violaceous, more or less translucently striate pileus. Basidiospores with well-defined angles indicate that the species belongs to section Dichroa and this is also confirmed by the molecular data. Other representatives of the section have larger basidiomata with blue pilei and stipes. Therefore, macromorphologically the basidiomata of this species, due to the combination of a pinkish or lilac pileus and a violaceous blue stipe, are more similar to E. callichroum, that differs, however, by its larger basidiomata, larger, differently shaped spores, and fertile lamella edge.

The basal grade

The term basal grade refers here to the papers of Morgado et al. (2013), and Baroni & Matheny (2011), in which the position of several clades basal in the Entoloma phylogeny is discussed. These basal clades shown in Fig. 62 include /Caeruleopolitum, /Prunuloides (sect. Madida), /Sphagneti, /Turfosa and /Vinaceum, as well as the singleton E. fusconigrum. The genus Entocybe (/Turfosa and /Vinaceum) is not accepted here, for obvious reasons, as accepting it in our opinion would lead to excessive splitting of the genus Entoloma as has happened in Rhodocybe s.l.

Fig. 62.

Maximum Likelihood (RAxML) phylogenetic tree based on nrDNA ITS sequences of the basal grade (sect. Madida, /Turfosa, /Vinaceum, /Caeruleopolitum and /Sphagneti) of the genus Entoloma. ML bootstrap support values ≥ 50 % are presented at the brackets. Sequences used from public databases (i.e. GenBank, UNITE) contains accession numbers, while for the newly generated sequences only voucher numbers are indicated. The country of origin is indicated in any case. Type specimens are shown as abbreviations: HT (holotype), NT (neotype), ET (epitype). The scale bar indicates expected changes per site per branch.

Entoloma fusconigrum G.M. Jansen, Dima, A.M. Ainsw., M.A. Roberts & Biketova, sp. nov. MB 860439. Fig. 63.

Fig. 63.

Entoloma fusconigrum (A, C, E. K(M)265247; B, D, F. L0607801, holotype). A–C, E. Habit. D. Basidiospores. F. Pileipellis. Photos: A, C, E by M.A. Roberts; B, D, F by G.M. Jansen. Scale bars: 1 cm (habit), 10 μm (microstructures).

Etymology: fuscus (Lat.) – brown, niger (Lat.) – black, referring to the colour of the basidiomata.

Typus: The Netherlands, prov. Flevoland, Dronten, Roggebotzand, near conifers on sandy soil, 7 Mar. 2014, M. Kroese & G.M. Jansen (holotype L0607801); ITS sequence, GenBank PX412036.

Description: Basidiomata collybioid. Pileus 20–45 mm wide, convex, flattening, sometimes with low or more prominent umbo, with involute margin often becoming wavy, indistinctly hygrophanous, not translucently striate, brown to very dark brown or almost black, uniformly coloured, glabrous or with fine, white crystals, particularly around centre. Lamellae distant to moderately distant (L = 40–50, I = 1–4), adnate to emarginate with decurrent tooth, subventricose, up to 2.0 mm broad, light brown, with entire, concolourous edge, slightly veined on the sides. Stipe 35–55 × 4–10 mm, slightly and gradually broader towards the base, fibrous, beige with darker brown, longitudinal fibrils; base with white tomentum. Context thin, brown in cortex, whitish inside. Smell farinaceous. Taste not known. Basidiospores (40/2) 6.0–8.0 × 5.0–7.0 μm, on average 6.9–7.0 × 6.0–6.2 μm, Q = 1.00–1.30, Qav = 1.10–1.15, iso- to subisodiametrical, rounded angular, thin-walled. Basidia 30–40 × 8–11 μm, 4-spored, clamped. Lamellar edge fertile, no cystidia present. Hymenophoral trama regular; tramal hyphae 3–20 μm wide, inflated and appearing constricted at the septa. Pileipellis a cutis with transitions to a trichoderm, of cylindrical, 2–8 μm wide hyphae; terminal elements of suprapellis subclavate to clavate with light brown, intracellular pigment. Stipitipellis consists of a cutis of loose, narrow, 6–9 μm wide hyphae; caulocystidia not observed. Clamp-connections present in all tissues.

Habitat and distribution: Terrestrial; gregarious in coniferous debris or in litter in mixed woodland (Quercus, Corylus, Pinaceae). Currently only recorded at two sites (both in March): the holotype was collected near Pinaceae in The Netherlands and the paratype was found on a wooded embankment in North Wales, UK.

Additional material examined: UK, Wales, Denbighshire (VC50), Melin-y-Wig, in woodland, 14 Mar. 2022, M.A. Roberts [K(M)265247].

Notes: This remarkable dark-coloured species was initially identified as E. pseudoturbidum on account of the small, rounded, thin-walled spores, typical for the sect. Turfosa (= sect. Trachyospora). However, the phylogeny shows that this species has an isolated position in the tree, sister to the /Caeruleopolitum clade, and very distant, also morphologically, from E. pseudoturbidum in sect. Turfosa. The Welsh collection was initially identified as E. cf. chytrophilum because of the macroscopical similarity, but that species belongs to the phylogenetically very distinct subgenus Leptonia and differs considerably in micromorphology (Noordeloos et al. 2022a).

/Turfosa clade – sect. Turfosa

Entoloma sect. Turfosa (Romagn.) Noordel., Persoonia 10: 529. 1980.

Basionym: Rhodophyllus sect. Turfosi Romagn., Bull. Mens. Soc. Linn. Soc. Bot. Lyon 43: 332. 1974. Type species: Entoloma turbidum (Fr.) Quél.

Synonym: Entoloma sect. Trachyospora Largent, Mycologia 66(6): 995. 1974.

Entocybe T.J. Baroni et al., N. Amer. Fungi 6(12): 8. 2011. Type species: Entoloma trachyosporum Largent.

The /Turfosa clade partly coincides with the genus Entocybe, but we do not accept the latter on a generic level. We prefer treating this clade as a section within Entoloma, for which the name Turfosa is available. Romagnesi’s revised classification was published in November 1974, while Largent’s study was published on 31 December 1974, so Turfosa has priority over Trachyospora. The position of the /Vinaceum clade, originally included in the concept of Entocybe, is unclear (Fig. 62), and should therefore be excluded from sect. Turfosa in strict sense (see also below). This will eventually necessitate an amended concept of sect. Turfosa. Species in both clades have rather small, thin-walled spores, that are only weakly angled, a reason why they sometimes have been confused with Rhodocybe sensu stricto species. However, the ultrastructure of the spore wall is typically entolomatoid, as is demonstrated in Co-David et al. (2009), and the phylogenies confirm the inclusion of this clade in Entoloma. The basidiomata are usually mycenoid or collybioid, often with a fusiform stipe with a tapering base, and the pileipellis is often (sub)viscid. The species of this section are widespread in the Northern and Southern Hemispheres (Noordeloos & Gates 2012).

Entoloma myochroum Noordel. & E. Ludw. ex Noordel. & E. Ludw., sp. nov. MB 860440. Fig. 64A, B.

Fig. 64.

A, B. Entoloma myochroum (A. Weholt E14-19; B. L0608353, holotype). A. Habit. B. Basidiospores. C–G. Entoloma pseudoturbidum (C, D, G. Weholt E2-23; E, F. L0608377, epitype). C–F. Habit. G. Basidiospores. Photos: A, C, D, by Ø. Weholt; B by M.E. Noordeloos; E, F by H. Pras; G by G.M. Jansen. Scale bars: 1 cm (habit), 10 μm (spores).

Synonym: Entoloma myochroum Noordel. & E. Ludw., in Noordeloos, Entoloma s.l., Fungi Europaei vol. 5a: 839. 2004, MB 504388, nom. inval., Madrid, Art. 40.5; holotype designated in two herbaria.

Etymology: μῦς (Greek) – mouse, referring to the mouse-coloured pileus.

Typus: Germany, Rheinland-Pfalz (Eifel), Strohner Schweiz, in Fagus wood on basalt, 6 Oct. 1990, H. Ebert (holotype L0608353, failed in sequencing both with Sanger and NGS methods).

Description (amended here): Basidiomata robust, tricholomatoid. Pileus 40–100 mm wide, convex then expanding to plano-convex with low umbo, finally concave with depressed centre, with involute margin, hygrophanous or not, not translucently striate, mousegrey with slight ochre tinge, subviscid, glabrous, shining. Lamellae crowded (L = 40–60, l = 5–7), adnate-emarginate with short decurrent tooth, narrow, subventricose, white then pink with irregular, concolourous edge. Stipe 80–95 × 10–18 mm, cylindrical-flexuous, irregularly shaped, whitish, longitudinally fibrillose. Context thin in pileus, thick and solid in stipe. Smell and taste slightly farinaceous. Basidiospores (60/3) 6.0–9.0(–10.0) × 6.0–8.5 μm, on average 6.9–8.5 × 7.0–7.7 μm, Q = 1.00–1.35, Qav = 1.10–1.15, iso- to subisodiametrical, 4–6-angled in side view, often with rounded angles. Basidia 24–45 × 7–11 μm, 4-spored, clamped. Lamella edge fertile. Cystidia absent. Pileipellis a narrow cutis of cylindrical, 2–7 μm wide hyphae, gradually passing into pileitrama; pigment brown, intracellular. Hymenophoral and pileitrama regular, made up of short, inflated elements. Stipitipellis a cutis of cylindrical hyphae. Caulocystidia absent. Clamp-connections present in all tissues.

Habitat and distribution: Terrestrial in woodland, associated with Fagus or Quercus. Very rare, only known from Germany and Norway.

Additional material examined: Norway, Hordaland, Stord, Agdestein, on soil in low-herb oak forest, 6 Sep. 2019, T.E. Brandrud, NMC2019-156 (O-F-256451); Østfold, Fredrikstad, Torsnes, Nes, on soil under Quercus, 23 Aug. 2023, Ø. Weholt, E4-23 (O-F-77031); Østfold, Hvaler, Vesterøy, Bankerød, on soil under Quercus and Populus, 22 Aug. 2019, Ø. Weholt, OW-E14-19; ibid., 6 Oct. 2020, Ø. Weholt, OW-E8-20; ibid., 12 Oct. 2020, Ø. Weholt, OW-E21-20; ibid., 12 Oct. 2020, Ø. Weholt, OW-E22-20.

Notes: Entoloma myochroum is a remarkable species with a tricholomatoid habit, reminiscent of E. sinuatum, E. lividoalbum, E. noordeloosii or other species from the /Rhodopolia clade (i.e., subgen. Entoloma), differing mainly by the small, often rounded, 4–6-angled spores. Phylogenetically, it is not related to subgen. Entoloma, but it is rather close to E. nitidum (16 substitution and indel differences in the ITS region) in the basal grade, which makes it a member of sect. Turfosa (i.e. Entocybe as circumscribed by Baroni et al. 2011). Most species in this clade have small, rounded-angular spores. Sequencing of the holotype of E. myochroum failed in sequencing both with Sanger and NGS methods. The concept used here is consistent with the original description and there are not any morphological discrepancies in the specimens from Norway, which would indicate a potential different species. Good material from the type-area is needed to designate an epitype for this species.

Entoloma pseudoturbidum (Romagn.) M.M. Moser, Beih. Sydowia 8: 269. 1979. MB 313798. Fig. 64C–G.

Basionym: Rhodophyllus pseudoturbidus Romagn., Bull. Mens. Soc. Linn. Soc. Bot. Lyon 43: 386. 1974. MB 322736.

Synonym: ?Entoloma turbidum var. pachylamellatum Noordel., Persoonia 11: 222. 1981. MB 117682.

Typus: France, Dept. Oise, Forêt de Hez-Froidmont, 18 Nov. 1960, J. Gasnier (holotype Romagnesi 58.432 in PC, not sequenced); The Netherlands, prov. Drenthe, Norg, 8 Nov. 2013, H. Pras (epitype L0608377, designated here, deposited at L, MBT 10028214); ITS sequence, GenBank PX412062.

Description (amended here): Basidiomata: tricholomatoid. Pileus 20–85 mm wide, bluntly conical or hemispherical, expanding to plano-convex with broad umbo, often situated within a slight depression, with margin slightly rounded-incurved when young, becoming straight or even reflexed and translucent with age, hygrophanous, not translucently striate or at outer margin only, dark umber brown or sepia with darker umbo, slightly pallescent to greyish brown on drying, subviscid when moist, becoming strongly radially fibrillose-virgate, subrugulose or minutely squamulose, and satiny shiny on drying. Lamellae distant (L = 32–40, l = 1–3), with numerous lamellulae, ascending and almost free with very small tooth on stipe, ventricose, 7–11 mm broad, greyish white then grey brown with pink tinge, finally reddish brown, with distinctly irregular, concolourous edge, sometimes transversally veined. Stipe 30–110 × 4–13 mm, cylindrical or distinctly broadened at base, greyish or greyish-brownish, grey, steel grey then umber brown, almost concolourous with pileus, distinctly fibrillose striate lengthwise, sometimes twisted. Context thick, rather fragile, whitish but brownish when wet. Smell and taste strongly farinaceous. Basidiospores (60/4) 6.5–8.0 × 5.5–7.5(–8.0) μm, on average 7.1–7.5 × 6.0–7.0 µm, Q = 1.00–1.30, Qav = 1.15–1.20, thin-walled, subglobose in outline with 5 to 9, rather weak angles in side view. Basidia 20–35 × 6–11 µm, 4-spored. Lamella edge fertile. Cheilocystidia absent. Hymenophoral trama regular, made up of inflated, up to 20 µm wide elements. Pileipellis two-layered, epicutis and ixocutis, made up of 2.5–6 µm wide, cylindrical hyphae, over a subpellis made up of short, inflated, up to 25 µm wide elements. Pigment brown, intracellular. Stipitipellis a cutis of cylindrical hyphae. Caulocystidia absent. Clamp-connections abundant in all tissues.

Habitat and distribution: Terrestrial in semi-natural grassland or on grassy roadside near Picea, Fagus, or Quercus. Known from France, Norway, and The Netherlands.

Additional material examined: Norway, Nordland, Alstahaug: Skålvær, Buøya, on soil in old pasture, 17 Sep. 2004, A.B. Stærnes, J.B. Jordal, A. Knutsen, P. Fadnes & D. Pettersen (O-F-67221); Østfold, Fredrikstad, near Borge Varde, open deciduous woodland, 6 Aug. 2023, Ø. Weholt, E2-23 (O-F-77032); Østfold, Hvaler, Bankerud, Vesterøy, open woodland with Quercus, 22 Aug. 2019, Ø. Weholt, E14-19 (O-F-77034) – not included in the phylogenetic analysis; 12 Oct. 2020, Ø. Weholt, E21-20 (O-F-77033) – not included in the phylogenetic analysis.

Notes: Despite the fact that unfortunately no molecular data are available from the holotype, we conclude, after a careful comparison with the original description and personal microscopic notes on the type material, that we should refer our specimens to E. pseudoturbidum. This species is very close to E. turbidum, with a very similar microscopy, characterised by small, rounded spores. The main differences are found in the dark pilei in E. pseudoturbidum that become radially fibrillose, rugulose or squamulose with age, the somewhat more distant lamellae, and dark stipe surface, in addition to its phylogenetic position. Furthermore, it seems to prefer more or less open grasslands or roadsides, whereas E. turbidum is most frequently found in heathlands and forests on acidic soils.

/Vinaceum clade

The /Vinaceum clade has an unstable position in our analyses. In the overview tree presented in Fig. 1 it clustered sister to the /Prunuloides clade (= sect. Madida) without support, while in the detailed analysis of the basal grade (Fig. 60), it formed a sister and basal clade of both /Prunuloides and /Turfosa (sect. Turfosa) with high support (ML BS = 95 %).

Entoloma vinaceum (Scop.) Arnolds & Noordel., Persoonia 10(2): 298. 1979. MB 313847.

Basionym: Agaricus vinaceus Scop., Fl. carniol., Edn 2 (Wien) 2: 444. 1772. MB 451282.

Synonyms: Entoloma vinaceum var. fumosipes Arnolds & Noordel., Persoonia 10(2): 298. 1979. MB 348093.

Entoloma fuliginarium P. Karst., Hedwigia 31: 292. 1892. MB 194178.

Typus: Holotype not existing, described from Slovenia. Germany, Hessen, Burgwald, Rotes Wasser/Franzosenwiesen, poor grassland, 25 Nov. 2016, K. Reschke, KaiR283 (neotype B 70 0105504, designated here, deposited at B, MBT 10028215); ITS sequence, GenBank PX412073.

Additional material examined: Finland, Kanta-Hämä, Tavasta, Mustiala, among mosses, Sep. 1891, P. Karsten (H, holotype of E. fuliginarium; ITS sequence, GenBank PX444435). Norway, Innlandet, Oppland, Lunner, Morstadhaugen, oligotrophic, on soil in xeric (lichens, Calluna) pine forest, 4 Oct. 2001, E. Bendiksen, EB 204/01 (O-F-169164); ibid., 29 Sep. 2004, E. Bendiksen, 246/04 (O-F-165807); S. Korsvatnhaugen, on soil in old Vaccinium myrtillus-Picea forest, 9 Oct. 2015, E. Bendiksen, EB 279/15 (O-F-252032); Oslo, Grorud, Frankrig N, on soil in mixed forest, 26 Sep. 1984, E. Bendiksen, EB 362/84 (O-F-169415); Troms, Storfjord, Helligskogen, on soil in mixed birch-willow forest, terrestrial in very poor Vaccinium-Empetrum heath, 17 Aug. 1992, M.E. Noordeloos (TROM-F-34-1). The Netherlands, prov. Drenthe, Westerbork, Hullenzand, 3 Nov. 1976, E.J.M. Arnolds, 3728 (L0537408, isotype of Entoloma vinaceum var. fumosipes; ITS sequence, GenBank PX401861).

Notes: Entoloma vinaceum is an inconspicuous species, not uncommonly found in semi-natural grasslands and heathlands, preferably late in the season (see e.g. Brandrud et al. 2019). It is also one of the few Entoloma species growing in moss-rich, oligotrophic spruce and mixed spruce/pine forests in Fennoscandia. Like in the closely related E. zuccherellii, and in the North American E. trachyosporum, colour varies within the species, which includes populations with violaceous tinges in either pileus or stipe. These colour forms do not deserve a separate taxonomic rank.

Entoloma zuccherellii (Noordel. & Hauskn.) Noordel. & Co-David, Persoonia 23: 175. 2009. MB 491771.

Basionym: Rhodocybe zuccherellii Noordel. & Hauskn., Boll. Gruppo Micol. ‘G. Bresadola’ (Trento) 43(3): 29. 2000. MB 482854.

Synonym: ?Entoloma pluteisimile Noordel. & C.E. Hermos. [as ‘pluteisimilis’], in Noordeloos, Entoloma s.l., Fungi Europaei vol. 5a: 918. 2004. MB 491771.

Entoloma sclerotiogenum Fern. Caball., Higelmo, Català & Vila, Errotari 9: 122. 2012. MB 800680.

Entoloma vinaceum var. violeipes Arnolds & Noordel., Persoonia 10(2): 299. 1979. MB 348094.

Notes: Several collections under the name E. pluteisimile, E. zuccherellii, and the holotypes of E. vinaceum var. violeipes, and E. sclerotiogenum cluster together as a sister species of E. vinaceum. Unfortunately, we do not have ITS sequences of the holotypes of E. pluteisimile and E. zuccherellii for comparison. For the time being we assume that all names refer to the same species. Entoloma zuccherellii has priority.

Additional material examined: The Netherlands, prov. Drenthe, Westerbork, Mantinger Zand, in heathland on sandy soil. 13 Nov. 1974, E.J.M. Arnolds, 3322 (L0423731, holotype of Entoloma vinaceum var. violeipes; ITS sequence, GenBank PX401862); prov. Overijssel, Rijssen, Rijsserberg, on rotten stem of Fagus, 22 Feb. 2022, I. Wind (L0607274); prov. Noord Holland, de Bijvanck, on trunk of Quercus, 3 Jan 2023, G.M. Jansen & M.J.C. van der Vegte (L4343916). Ukraine, Uholka Shyrokyi Luh, old Fagus sylvatica forest, among litter, 8 Oct 2013, F. Popa & K.-H. Rexer, KR12754 (MB).

/Prunuloides clade – sect. Madida

Entoloma sect. Madida (Romagn.) N. Schwab, Index Fungorum 541: 1. 2023. MB 559994.

Basionym: Rhodophyllus sect. Madidi Romagn. 1974, Bull. Mens. Soc. Linn. Soc. Bot. Lyon 43(9): 332. 1974. MB 634425.

Type species: Entoloma madidum Gillet

Notes: The /Prunuloides clade coincides with Entoloma sect. Madida and contains species usually with a tricholomatoid, rarely mycenoid habit, a tapering stipe, frequently with yellow tinges at the base, some with bright lilac blue tinges, and relatively small, iso- or subisodiametrical spores with pronounced angles. It coincides with clade B2 in the phylogeny of Morgado et al. (2013), and it is clearly separated from the /Turfosa clade (Entocybe, clade B1 in Morgado et al. 2013). Species in this clade can be found in both the Northern and Southern Hemispheres. They are often rather indicative of high natural/ecological quality, in particular in grassland habitats, and most of the known species are on local and international red data lists (Fraiture & Otto 2015). The species complex around E. bloxamii is rather diverse, and several new species have been described in recent years. In this paper we add another new one, see E. weiriorum below, so far only known from the United Kingdom. There is a great genetic diversity in this clade, which is not always reflected in clear cut morphological concepts. The ITS barcodes are useful for identification purposes. Entoloma inopiliforme, ranged in the synonymy of E. prunuloides in earlier works, is now reinstated, and fully described based upon a study of the holotype and several recent collections.

Entoloma inopiliforme Bon, Doc. Mycol. 12(46): 32. 1982. MB 109748. Fig. 65A–D.

Fig. 65.

A–D. Entoloma inopiliforme (A, C. Carbone 13-Oct-2012, epitype; B. DB6574; D. L0608110). A–C. Habit. D. Basidiospores. E, F. Entoloma weiriorum (K-M000141043, holotype). E. Habit. F. Basidiospores. Photos: A, C by M. Carbone; B by B. Dima; D by P. Salzmann; E by T. Rogers; F by J. Weir. Scale bars: 1 cm (habit), 10 μm (spores).

Replaced synonym: Entoloma inocybiforme Bon, Doc. Mycol. 10(37–38): 90. 1980. MB 113834, nom. illegit., Madrid, Art. 53.1, non Entoloma inocybiforme Murrill, N. Amer. Fl. (New York) 10(2): 120. 1917. MB 151697.

Typus: France, Dept. Somme, Abbeville, in calcareous grassland, date not given, M. Bon, Bon 79111804 (holotype in LIP, failed in sequencing both with Sanger and NGS methods). Italy, Piemonte, Alessandria, Borghetto di Borbera, 330 m.a.s.l., on soil in mixed forest with Castanea sativa, Populus tremula and Quercus pubescens, 13 Oct. 2012, M. Carbone & F. Calledda (epitype L0607181, designated here, deposited at L, MBT 10028216); ITS sequence, GenBank PX412042.

Description (amended here): Basidiomata tricholomatoid, often rather robust. Pileus 20–70 mm wide, conical then expanding to conico-convex, often with a broad umbo, not distinctly hygrophanous or translucently striate, initially rather dark sepia brown, grey brown, or with a purple tinge, often paler toward margin and somewhat marbled-spotted with paler and darker lines and spots, when old and dry often more ochre brown, waxy to subviscid when moist, soon dry, distinctly and often strongly radially fibrillose. Lamellae moderately distant (L = 30-40, l = 3-5), adnate-emarginate, ventricose, whitish to pale grey then pink, finally sordid pink, with subentire, concolourous edge. Stipe 25–80 × 4–12 mm, often tapering towards base, white, pale grey or, in older stages, sometimes tinged ochre, particularly in the middle, innately fibrillose, dry. Context white, firm. Smell somewhat aromatic, fruity, not very strong. Taste mild to slightly rancid. Basidiospores (80/5) 7.0–10.0 × 6.0–8.0 μm, on average 8.0–8.5 × 7.0–7.3 μm, Q = 1.00–1.30, Qav = 1.10–1.20, iso- to subisodiametrical, 5–6-angled with very rounded outline. Basidia 35–60 × 9–14.5 μm, 4-spored, clamped. Lamella edge fertile, cystidia absent. Pileipellis a thin (ixo)cutis of cylindrical, 2.5–7 μm wide hyphae; subpellis made up of inflated-fusiform or sausage-shaped elements, 40–85 × 15–25 μm; pigment pale brownish, intracellular in supra- and subpellis, sometimes membranal, not encrusted, in subpellis. Stipitipellis a cutis of cylindrical, 2.0–6.0 wide hyphae. Caulocystidia not observed. Clamp-connections present in all tissues.

Habitat and distribution: In calcareous grasslands and in mixed forest on calcareous soil. So far known from Austria, France, Germany, Hungary, Italy, and The Netherlands.

Additional material examined: Austria, Niederösterreich, Hinterbrühl, Sparbach, Naturpark, in calcareous forest, 6 Nov. 2008, M. Beisenherz, Herbarium Hausknecht 2773.1 (WU-Myc 28935). Germany, Sachsen, Geyer, Hermannsdorfer, Wiesen, calcareous grassland, 6. Oct. 2023, A. Karich, IHI-23Ent07 (GLM-F139803). Hungary, Vas, Őrség NP, Szalafő, on soil in the margin of a mixed forest with Pinus, Quercus, Fagus, Carpinus and Picea, 30 Sep. 2017, B. Dima, DB6574 (ELTE). The Netherlands, prov. Limburg, Stokhem, Dikkersweide, calcareous grassland, 23 Aug. 2017, F. Salzmann & R. Salzmann, PSLhg00135 (L0608110).

Notes: Entoloma inopiliforme was described by Bon, initially as E. inocybiforme, which, however, was illegitimate being a later homonym of E. inocybiforme Murrill. Despite several attempts, including the FunDive project, we failed to sequence the holotype, kindly provided by R. Courtecuisse. However, in view of the original diagnosis giving way for the current interpretation, and striking similarly with the recent collections, it was decided to accept the name E. inopiliforme for our species, and an epitype was designated. Entoloma inopiliforme is distinguished by the often striking purple brown tinged pileus, that becomes medium brown with age, and the often very clearly radially fibrillose pileus, hence the name E. inopiliforme. In the phylogeny, it forms a sister group to E. luteobasis in the /Bloxamii subclade, albeit without support.

Entoloma weiriorum A.M. Ainsw., B. Douglas, D.J. Harries, Speed, T. Rogers, Watt, Suz & Dima, sp. nov. MB 860441. Fig. 65E, F.

Etymology: Named for John & Sheila M. Weir, who collected the holotype.

Typus: UK, England, West Lancashire (VC60), Silverdale, Eaves Wood, in open, mixed woodland, 20 Sep. 2005, J. Weir & S.M. Weir (holotype K-M000141043); ITS sequence, GenBank MF967051.

Description: Basidiomata tricholomatoid. Pileus 30–55 mm wide, bluntly conical with involute margin, becoming conico-convex then flattening to convex with broad umbo and wavy margin that may remain slightly involute, dark violaceous blue grey becoming more brownish at maturity especially at the umbo, glabrous and tacky when damp, becoming innately, radially fibrillose and sometimes splitting around the margin. Lamellae crowded (L = 60–80, I = 3), narrowly adnate (emarginate), subventricose, up to 3.0 mm broad, creamy white when young, with entire, concolourous edge, occasionally veined on the sides. Stipe 35–55 × 7–12 mm, cylindrical with tapering base, white with dark violaceous blue grey longitudinal fibrils that become more grey brown when mature, base creamy white or tinged yellow and lacking fibrils. Context pale brown. Smell weakly farinaceous. Taste not recorded. Basidiospores (40/2) 7.0–9.0 × 6.5–8.5 μm, on average 7.9–8.0 × 7.6 μm, Q = 1.00–1.10, Qav = 1.03–1.05, isodiametrical to subisodiametrical. Basidia 40–60 × 9–12 μm, 4-spored, clamped. Lamellar edge fertile, no cystidia present. Hymenophoral trama hyphae 5–25 μm wide, inflated and constricted at the septa. Pileipellis an ixocutis of cylindrical to slightly torulose, 2–7 μm wide hyphae, with blue intracellular pigment. Clamp-connections present in all tissues.

Habitat and distribution: Terrestrial, in open, semi-natural, mixed woodland on thin calcareous soils overlying limestone. Currently only recorded at two sites, both of which are in Northwest England: the holotype was collected from a group of 15 basidiomata found in a grassy glade and the paratype was a singleton collected approximately 2 km away under Taxus near an open grassy area.

Additional material examined: UK, England, West Lancashire (VC60), Silverdale, Gait Barrows, Grid Ref. SD483775, woodland, 27 Sep. 2020, H. Speed, NWFG01 (K-M001442646).

Notes: If historical collections exist, they are likely to have been assigned to E. bloxamii. With currently available data, E. weiriorum seems morphologically and ecologically very close to the modern, epitypified concept of E. bloxamii and, unless further discriminatory characters are forthcoming, DNA barcode analysis is therefore recommended to assign material of E. bloxamii s.l. to the correct species. The ITS sequence of the holotype of E. weiriorum (as Entoloma sp.), as well as coloured photographs (Figs 2, 7D) were originally published in Ainsworth et al. (2018).

SUPPLEMENTARY MATERIAL

Table S1

Sequences used in the phylogenetic analyses. Newly generated sequences for this study are marked in boldface. The taxonomic labels of the sequences taken from public databases (i.e. GenBank, UNITE) are indicated in brackets. Sequences not included in the phylogenetic analysis are marked with an asterisk (*).