Expanding Lycogala: twenty-four new species, their morphology and phylogenetic relationships

D Leontyev; Y Ishchenko; M Leontieva; I Yatsiuk; O Shchepin; W-L Song; SL Chen; E Moroz; M Schnittler

doi:10.3114/fuse.2025.16.7

. 2025 Jul 4;16:93–146. doi: 10.3114/fuse.2025.16.7

Expanding Lycogala: twenty-four new species, their morphology and phylogenetic relationships

D Leontyev ^1,^2,^*, Y Ishchenko ³, M Leontieva ², I Yatsiuk ^4,⁵, O Shchepin ², W-L Song ⁶, SL Chen ⁶, E Moroz ³, M Schnittler ²

PMCID: PMC12486227 PMID: 41041170

Abstract

The genus Lycogala was historically considered a small, morphologically uniform group of myxomycetes, with its classification remaining largely unchanged for most of the 20^th century. However, recent molecular studies have revealed exceptional cryptic diversity within the genus, challenging its traditional species delimitations. This study continues the taxonomic reassessment of Lycogala, integrating three-gene phylogenies and morphological analyses of 716 specimens from four continents. A total of 706 nucSSU, 273 mtSSU, and 130 COI sequences were analysed to delimit species within the genus using recombination test and distance-based delimitation. As a result, 716 specimens were assigned to 93 nucSSU ribogroups, which were further grouped into 63 putative morphological species. Of these, only 20 had been formally described prior to this study. Herein, we describe an additional 24 species, significantly expanding the known diversity of the genus. Phylogenetic analyses suggest the division of Lycogala into five major clades, which correspond to distinct morphological traits, supporting the proposal of five new sections within the genus. The study also confirms that L. epidendrum s. str. exhibits significant genetic polymorphism, with at least 29 subgroups detected. However, species delimitation within L. epidendrum remains challenging due to conflicting results from genetic markers and the presence of recombined genotypes. The study underscores the necessity of integrating molecular and morphological approaches for resolving Lycogala taxonomy and highlights the potential for further discoveries in myxomycete diversity.

Citation: Leontyev D, Ishchenko Y, Leontieva M, Yatsiuk I, Shchepin O, Song W-L, Chen SL, Moroz E, Schnittler M (2025). Expanding Lycogala: twenty-four new species, their morphology and phylogenetic relationships. Fungal Systematics and Evolution 16: 93–146. doi: 10.3114/fuse.2025.16.7

Keywords: ASAP analysis, myxomycetes, new taxa, phylogeny, reproductive isolation, ribogroup, species delimitation, systematics

INTRODUCTION

The genus Lycogala is one of the earliest myxomycete taxa discovered, with four ‘classical’ species formally described in the 18^th–19^th centuries. By the early 20^th century, taxonomists had nearly lost interest in this genus due to its relatively simple morphology and low variability. All Lycogala species form sessile sporocarps (misinterpreted as aethalia for a long time, see McHugh & Reid 2008), coloured in dull shades of brown and grey, lacking stalks, columellae, or a distinct hypothallus (except for L. flavofuscum). Ornamentation of spores and capillitium show little variation within the genus. As a result, no significant progress in the taxonomy of Lycogala was observed throughout the 20^th and early 21^st centuries. In 2022, the genus included only seven recognized species, among which the abovementioned four ‘classical’ taxa (L. conicum, L. flavofuscum, L. epidendrum, and L. exiguum) were consistently referenced in literature, while the rest were known mainly from their original descriptions. The ‘classical’ species were distinguished mostly by macroscopic traits, such as the size and shape of the sporocarps, reducing the need for detailed microscopic examination of collected material. Many authors chose not to collect herbarium specimens of Lycogala, merely recording them in field notes (Leontyev et al. 2023a).

Everything changed with the critical revision of the genus Lycogala based on molecular and morphological data (Leontyev et al. 2022). It was demonstrated that the peridium (the protective covering of the fruiting bodies) exhibits in this genus an exceptional structural diversity, and that patterns in its structure correlate with barcoding data from the 18S rDNA (nucSSU) marker. Subsequently, it became clear that groups of specimens with similar structure of the peridium display characteristics of distinct species, as evidenced by a barcode gap and reproductive isolation tests (Leontyev et al. 2023a). The number of putative species identified through molecular methods exceeded all expectations: the 2022 study reported 45 species, and the 2023 study identified 66, with mathematical predictions suggesting the total number could exceed 100. This is the highest number of species ever detected during a critical revision of a myxomycete taxon. Nearly all undescribed species discovered in these studies were identified in herbarium collections labelled as L. epidendrum, meaning that uncovering the hidden diversity of Lycogala essentially amounted to studying the L. epidendrum agg. This taxon, long considered as one of the most mundane representatives of the myxomycetes, was revealed to be a highly complex group comprising dozens of unknown species.

In 2023, descriptions of 15 new species within L. epidendrum agg., primarily from Europe, were published (Leontyev et al. 2023b). The authors identified novel diagnostic criteria for species delimitation, including the pigmentation of immature fruiting bodies, the colour of fresh spore mass, the shape and mutual arrangement of peridial vesicles, and the presence of crystalline and oily deposits within them. Traits such as capillitium and spore ornamentation, traditionally given greater importance in myxomycete taxonomy, appeared to be less useful for Lycogala. New species partitioning was supported by nucSSU and cytochrome oxidase subunit I gene (COI) phylogenies. However, only the first genetic marker, nucSSU, could be used to barcode all samples. The COI sequences were obtained for approximately one-third of the collections due to limited primer specificity.

The discovery of new Lycogala species sparked interest in the scientific community. Between 2023 and 2025, regional biodiversity surveys were published for countries such as Belarus, China, Norway, and Ukraine, reporting new occurrences of the recently described taxa (Johannesen & Vetlesen 2024, Leontyev et al. 2024, Song et al. 2024, Yatsiuk et al. 2024). Data on occurrences of these species also appeared on platforms like GBIF and iNaturalist. Additional morphological observations were published as well, including the first documentation of immature fruiting bodies of L. fossiculatum (Johannesen & Vetlesen 2024). The species L. alisaulianovae was found to exhibit a unique blue colouration of the contents of immature sporocarps, a feature unprecedented in Reticulariaceae and rare among bright-spored myxomycetes in general (Johannesen & Vetlesen 2024).

The authors of new species understood that they were describing only a fraction of the revealed diversity. However, the differences between Lycogala species are often subtle, while intraspecific polymorphism, on the contrary, can be considerable. For this reason, the authors opted against a ‘turbo-taxonomic’ approach in favour of an integrative methodology (Riedel et al. 2013), and chose to follow the Good Taxonomic Practice rules developed for myxomycetes (Schnittler et al. 2025). In this paper, we present a continuation of our work, based on a three-gene phylogeny and morphological analysis of over 700 Lycogala specimens collected from Europe, Asia, America, and Australia.

MATERIALS AND METHODS

Collections

The material examined in this study consisted of 716 specimens of Lycogala, including 714 studied directly and two involved as a published DNA sequence (Table S1). Analysed specimens and sequences originate from 22 countries and eight macro regions: Europe (473), North Asia (13), South-East Asia (50), East Asia (74), Australia (54), North America (32), Central America (19), and South America (1) (Fig. 1).

Fig. 1. — Distribution map for all *Lycogala* specimens involved in this study, created in GPSVisualizer, www.gpsvisualizer.com.

Type collections of the species, described here, are kept in following collections: CWP (Herbarium of the H.S. Skovoroda Kharkiv National Pedagogical University, Kharkiv, Ukraine), TNSM (National Museum of Nature and Science, Tsukuba, Japan), MCCNNU (Microbial Cultures Centre of Nanjing Normal University, Nanjing, China) and HFNNU (Herbarium of Fungi of Nanjing Normal University, Nanjing, China). Type specimens marked with acronyms IY, JuKl, PMcD and sc are kept in the myxomycete section of the Herbarium of the University of Greifswald, Germany (GFW). All collections involved in the study are listed in Table S1.

Morphological study

Microscopic characters were studied with a Keyence VHX 7000 digital microscope (view in reflected light, RL) and a Leica DM2500 microscope in conjunction with a Flexacam C1 camera (view in natural and polarized transmitted light, TL and PL, respectively). Measurements of microscopic structures were carried out with the application Leica LAS X. Scanning electron microscopy was carried out with a Zeiss Evo LS10 device in the Institute of Microbiology, University of Greifswald.

To study variation in sporocarp size, nearly all available sporocarps were measured for every specimen. Thirty spores, 15 capillitium threads and, on average, 50 peridial vesicles were measured for at least two specimens from each ribogroup (groups of similar ribosomal haplotypes). Measurements of spores included ornamentation. The range of variation in size is given in descriptions as (minimum–) 25 % quartile – 75 % quartile (–maximum) for sporocarps, vesicles, and capillitium, while spore size is shown as (minimum–) Mean−SD – Mean+SD (–maximum). Quantitative values are rounded to two significant digits (three for values over 100), down if closer to the lower bound, up if closer to the upper bound, and the last digit was adjusted to 0 or 5. Raw measurement data are provided in Table S2.

Microscopic slides with peridium pieces were prepared using pure lactic acid as a mounting medium. Microscopy of spores and capillitium was carried out in lactic acid mixed with Methyl blue, as described before (Leontyev et al. 2023b). Microphotographs of capillitium and spores were processed with the program Sharpen AI (Topaz Labs, Dallas, Texas, US) to enhance visibility of the surface ornamentation.

Microphotographs not included in the figures of newly described species, along with photographic materials of previously described species and putative taxa not yet formally described (~6000 photographs), are available in the database on Zenodo (https://zenodo.org/records/14963023).

DNA studies

Here and after for the mtSSU gene we do not use the term 12S rDNA, since in myxomycetes the corresponding rRNA molecule has a variable weight (17S in dark-spored myxomycetes, see Jones et al. 1990, and unknown in bright-spored). For consistency, we also use the term nucSSU instead of 18S rDNA. Genomic DNA was obtained from spores and amplified following a protocol described earlier (Leontyev et al. 2023a). For the amplification of mtSSU sequences we used the primers and PCR protocol developed for Trichiales (García-Cunchillos et al. 2022). Purified PCR products were sequenced by Macrogen Europe (Netherlands). From one to four sequences were obtained for each specimen and each marker gene, using different primer pairs and forward or reverse primer of each pair. As a result, for this study we obtained 1109 DNA sequences (706 nucSSU, 273 mtSSU, 130 COI), including 631 sequences published here for the first time (301 nucSSU, 278 mtSSU, 52 COI) (Files S1–S3). Newly obtained sequences were deposited in NCBI GenBank under accession numbers PQ633663−PQ633955, PQ685819−PQ685961 (nucSSU), PQ633386−PQ633662 (mtSSU), and PQ628450−PQ628501, PQ728318−PQ728402 (COI). NCBI GenBank codes for all molecular barcodes are provided in Table S1. The first author obtained 698 partial sequences of nucSSU and 116 of cytochrome oxidase subunit I gene (COI), including 301 nucSSU, 278 mtSSU, 53 COI sequences published in this study for the first time. M. Leontieva obtained 278 mtSSU sequences. W.-L. Song and S.L. Chen obtained for this study 16 nucSSU and 16 COI sequences.

Phylogenetic analysis

All obtained chromatograms were checked and edited in Chromas v. 2.6.6 (https://technelysium.com.au/wp/chromas/) and collected in fasta files using BioEdit v. 7.2.5 (Hall 1999). Sequence sets were aligned in MAFFT webserver (Katoh et al. 2019) using the E-INS-I iterative strategy. Resulting alignments include 1582 (nucSSU), 452 (mtSSU), and 601 (COI) positions.

For the construction of the Maximum likelihood (ML) phylogenetic trees for each marker gene, the IQ-TREE webserver was used (Trifinopoulos et al. 2016). The best evolutionary model selected by ModelFinder (Kalyaanamoorthy et al. 2017) as implemented in IQ-TREE was GTR+F+I+G4 for nucSSU and mtSSU, while GTR+F+G4, TPM3+F+G4, and GTR+F+I+G4 were selected for the first, second, and third codon positions of the COI gene, respectively. Three types of branch support statistics were employed to evaluate the reliability of trees, including Felsenstein bootstrap with 200 pseudo replicates (Hoang et al. 2018), approximate Bayes test and Shimodaira-Hasegawa approximate likelihood ratio test (SH-aLRT). Trees were rooted and edited in FigTree v. 1.4.4 (Rambaut 2018).

For the three-gene phylogenetic analysis, sequence data from 191 specimens of Lycogala were selected, and additional 12 specimens of bright- and dark-spored myxomycetes were used as an outgroup. Two representative specimens per every nucSSU ribogroup were selected if possible (i.e. if the ribogroup was not represented by a singleton), with preference to those specimens for which sequences of other genes were also available. Sequences were concatenated using MEGA software (Tamura et al. 2021). To remove unalignable parts of sequences (helices), GBlocks (Castresana, 2000) software was used, with the block length and minimum number of sequences for a flank position tweaked to allow less stringent block selection (−b2 = b1+20; −b4 = 8); the rest of parameters were left as default. The concatenated alignment 1442 bp long was partitioned as follows: nucSSU 1–525; mtSSU 526–841; and COI 842–1442, with a separate partition assigned for each codon position.

Bayesian inference was performed on the same alignment with MrBayes v. 3.2.7a (Ronquist et al. 2012). Reversible model jump (NST = MIXED) was applied to explore all possible GTR-models with unlinked rates of reversible substitutions, stationary state frequencies, shape of gamma distribution and proportion of variable sites across partitions. Gamma-distributed rate heterogeneity across sites and a proportion of invariable sites were permitted. Four runs with 20 M generations were done starting with a random tree and utilizing four MCMC chains, with stop rule deactivated. Trees were sampled every 1000 generations, and 25 % fraction was discarded as burn-in. Results of the Bayesian analysis were examined in Tracer v. 1.7.1 (Rambaut et al. 2018). The analysis ended with convergence of parameters (combined ESS > 2000). However, topological convergence was not reached after this number of generations (ASDSF = 0.028). It resulted in the consensus tree with polytomies at deeper nodes. The analysis was repeated on the full (not trimmed) concatenated alignment with 2603 positions. After 20 M generations mixing was poor and neither parameter nor topology convergence was reached (combined ESS for many key parameters < 100, ASDF = 0.12). An additional 15 M generations did not improve convergence. Similarly, tuning the temperature of heated chains, simplification of partitioning and evolutionary models have not made any significant improvements to analyses. Overall, the Bayesian interference pointed at disagreements in topologies between employed genes.

The maximum likelihood single-gene trees were used to infer a species tree under the multi-species coalescent model (Rannala & Yang 2003) using wASTRAL v. 1.20.3.7 (Zhang & Mirarab 2022). The analysis was done with the default weighting mode (“hybrid”), 30 initial rounds of placements, 30 rounds of subsampling per exploration step and branch local posterior probability values (Sayyari & Mirarab 2016) written to the final species tree. Multiple sequenced individuals from the same putative or described species were marked to belong to one species.

Species delimitation

Preliminary species delimitation was carried out separately for each marker gene using the Assemble Species by Automatic Partitioning (ASAP, Puillandre et al. 2021) algorithm employing the Kimura (K80) 2.0 distance model. Five best scores were calculated for each marker.

The reproductive isolation was tested by checking correspondence between nucSSU, mtSSU and COI groups in specimens for which more than one marker was obtained (see explanation in Leontyev et al. 2023a). Each sequence variant (haplotype) of every gene was assigned a unique numeric code. The combined file was then put through the GUI python program LineChart (Shchepin et al. 2021), which visualizes the combinations of haplotypes that were observed in the studied individuals. Groups of connected haplotypes – those that appear as linked nodes on the recombination diagram – are considered as freely recombining.

RESULTS

Molecular delimitation of species

The nucSSU gene is widely used for molecular barcoding and species delimitation in myxomycetes (Leontyev & Schnittler 2017, 2022). The obtained 706 partial sequences of this gene were analysed by ASAP to provide the preliminary distance-based species delimitation scheme. Five best score partitions grouped our sequences in 83–107 putative species (Fig. S1). The lowest (best) score was obtained for the partition with 97 species hypotheses, designated here as ribogroups. With this partition, the Chao1 index predicts that the total number of ribogroups within Lycogala may reach 183. In the nucSSU phylogeny (see File S1), nearly all 97 ASAP-delimited ribogroups form monophyletic branches and correspond well to preliminary delineated morphological species. The partial exception is L. epidendrum s. str., an extremely variable taxon (Leontyev et al. 2023a), which the ASAP proposed to separate into five species (01j, 01n, 01o, 01q and the rest of subgroups). However, in the present paper we considered all L. epidendrum as a single ribogroup, taking into account that (i) subgroups 01n and 01q are not separated phylogenetically from the rest of the species, as seen from the nucSSU phylogeny, and (ii) that the delimitation of L. epidendrum subgroups strongly varies in ASAP analyses and single-gene trees based on other markers (see below). After fusion of all L. epidendrum groups, the total number of ribogroups assigned for the genus Lycogala reached 93. The numbering of ribogroups used in previous publications (Leontyev et al. 2023a, b) has been retained wherever possible.

The ASAP delimitation of mtSSU was carried out for 273 sequences, which represent 59 nucSSU-based ribogroups. The five best score partitions grouped our sequences in 75–89 putative species, with the lowest score obtained for 77 species (Fig. S2). Among them, 16 are sub-branches of L. epidendrum s. str. All others are congruent to the nucSSU ribogroups with minor modifications: rg08, 37, 47 are split in two, while related rg54 and 80 are merged into one.

The ASAP delimitation of COI was carried out for 130 sequences, which represent 31 nucSSU-based ribogroups. The five best score partitions grouped our sequences in 24–33 putative species, with the lowest score for 32 species (Fig. S3). Among them, three are sub-branches of L. epidendrum s. str. that are poorly represented in our COI alignment, and the rest corroborate nucSSU ribogroups, with one exception of related rg15 and 91, forming a single group in the COI delimitation.

The recombination test by LineChart revealed no evidence of recombination between ribogroups (Figs S4, S5). In all cases, specimens that belong to different nucSSU ribogroups also belong to different mtSSU and COI groups. This provides evidence that ASAP-based species hypotheses correspond to groups with mutually exclusive allele sets. For non-singleton ribogroups, intricate within-group connections are typical. Within L. epidendrum s. str., most of nucSSU phylogeny-based subgroups show an isolation from each other, but with a number of exceptions: within-group connections are found for clusters b1+b2+h+v+w, c+p, and d+i.

The species hypotheses, based on the recombination test results and the ASAP delimitations for three marker genes, are summarized in Fig. 2.

Morphological delimitation of species

Morphological examination of barcoded specimens allowed, in some cases, the grouping of related ribogroups into provisional morphological species complexes, including Lycogala botrydium (rg26, 93), L. densum sp. nov. (rg28, 85–87), L. guttatum sp. nov. (rg15, 84, 91), L. irregulare (rg02, 48, 70), L. oleocrystalliferum sp. nov. (rg52, 72, 74), L. pulchellum sp. nov. (rg54, 88), L. rubrosporum sp. nov. (rg53, 62), L. squamatum sp. nov. (rg27, 31, 61), and L. ustulatum sp. nov. (rg42, 83).

As a result of integrating molecular and morphological data, the 92 identified ribogroups were grouped into 63 morphological species. Of these, five were described before 2023, 15 were described in 2023 (Leontyev et al. 2023b), 24 are described in this study (Figs 5–7, 9–29), and an additional 18 remain undescribed, primarily due to insufficient data. A complete database of macro- and microphotographs taken for all these species, including the undescribed ones, is available on Zenodo (https://zenodo.org/records/14963023).

Fig. 5. — *Lycogala persicum sp. nov.* [A, I, M. AlMill01; B. HollyJones01; C–H, J–L. JuKl01 (holotype)]. **A, B.** Immature fructifications (A – courtesy of A. Millican; B – courtesy of H. Jones). **C, D.** Sporocarps. E. Peridium in RL. **F–H.** Peridial vesicles in TL. I. Capillitium and spores, methyl blue in lactic acid. J. Inner surface of the peridium, SEM. K. Capillitial tubules, SEM. L. Spore, SEM. M. Spores, methyl blue in lactic acid. The last spore is shown in optical section. Scale bars: A–C = 1 mm; D, E = 250 µm; F–H = 100 µm; I = 20 µm; J, K = 5 µm; L = 0.5 µm; M = 1 µm.

Fig. 7. — *Lycogala sphaeroconicum sp. nov*. [A–G, I–M. IY054 (holotype); H. EJ18190388]. A. Immature fructifications. **B, C.** Sporocarps. **D, E.** Peridium in RL. **F–H.** Peridial vesicles in TL. I. Capillitium and spores, methyl blue in lactic acid. J. Inner surface of the peridium, spores, SEM. K. Capillitial tubules, SEM. L. Spore, SEM. M. Spores, methyl blue in lactic acid. The last spore is shown in optical section. Scale bars: A, B = 1 mm; C = 0.5 mm; D = 250 µm; E–H = 100 µm; I = 10 µm; J = 5 µm; K, M = 1 µm; L = 0.5 µm.

Fig. 9. — *Lycogala umbrinum sp. nov*. [A−E, G, M. sc27827 (holotype); F. MSK-F43033; H–L. EJ22531365]. **A, B.** Sporocarps. **C, D.** Peridium in RL. **E–G.** Peridial vesicles in TL. H. Capillitium, methyl blue in lactic acid. **I–K.** Capillitial tubule, SEM. L. Spore, SEM. M. Spores, methyl blue in lactic acid. The last spore is shown in optical section. Scale bars: A = 1 mm; B–D = 0.5 mm; E–G = 100 µm; H, I = 5 µm; J, K, M = 1 µm; L = 0.5 µm.

Fig. 29. — *Lycogala asperum sp. nov*. [A–C, E–G, I–L. IY115 (holotype); D, H, M. TNSM12263]. A. Immature fructifications. **B, C.** Sporocarps. **D, E.** Peridium in RL. **F, G.** Peridial vesicles in TL. H. Capillitium and spores, methyl blue in lactic acid. I. Inner surface of the peridium, SEM. **J, K.** Capillitial tubules, SEM. L. Spore, SEM. M. Spores, methyl blue in lactic acid. The last spore is shown in optical section. Scale bars: A, B = 2 mm; C = 0.5 mm; D–G = 100 µm; H = 10 µm; I–K, M = 1 µm; L = 0.5 µm.

Deep phylogeny and delimitation of sections

A three-gene ML phylogeny based on 191 most representative specimens (Fig. 3) has shown that most of 63 putative species of Lycogala form five major clades (I–V), which, however, receive rather low support: I: 35.3/0.656/48, II: 85.2/0.92/8, III: 72.4/0.54/8, IV: 97.6/1/27, and V: 31.8/0.676/9 (SH-aLRT/aB/BS). Five species were not included into these groups and formed a staircase-like series of basal branches. A very similar grouping of species in five branches was obtained in a coalescent species tree (CST) (Fig. 4), based on single-gene trees (Figs S6–S8). In its unrooted version, all 63 species branch within five clades. The composition of these branches corresponds well with the ML phylogeny; exceptions include positions of L. botrydium (IV in ML / V in CST), L. pulchellum (II/IV), L. oncoides (basal clade/I), and several undescribed taxa. The statistical support values for branches in the coalescent tree are 0.67, 0.83, 0.67, 0.82, 0.83 for the clades I–V, respectively. Bayesian inference could not resolve deep branches of the genus Lycogala (Fig. S9). However, it reconstructed the clade I (support 0.83), II (0.82), most of V (0.53), and two main sub-branches of clades III (0.80, 0.53) and IV (1, 0.53).

Fig. 4. — Coalescent species tree based on three single-gene phylogenies built from 715 nucSSU, 278 mtSSU, and 130 *COI* sequences. Branch local posterior probabilities ≥ 0.8 are shown as hollow circles. Colours indicate the assignment of species to sections (the same as in Fig. 3); grey colour is used for species not assigned to any section.

Although branch supports do not allow for reliable conclusions about deeper phylogenetic relationships within the genus Lycogala, species included in the five reconstructed clades share a set of morphological characteristics, mainly related to the spatial arrangement and contents of peridial vesicles. Given that the present study identifies already 44 species within Lycogala (excluding several problematic taxa, see Lado 2005–2025), to facilitate orientation in this large genus we suggest to divide it into five sections.

TAXONOMY

Lycogala Adans., Fam. pl. 2:7. 1763.

Lycogala sect. Lycogala

Diagnosis: Section unites species with solitary peridial vesicles, rather irregular in shape and variable in size, with both oil and crystals absent.

Description: Sporocarps large, grouped, often deformed from mutual pressure. Vesicles under RL hardly visible, faint or distinct (L. maculatum); greyish patches of dried slime often present. Vesicles under TL loosely or densely (L. maculatum) distributed, solitary, variable in size, irregular in shape, light brownish to brown. Oil and crystals in vesicles absent or nearly absent. Capillitium ornamented with bracelets. Fresh spore mass coloured in pale colours: beige, dull pinkish.

Typus: Lycogala epidendrum (L.) Fr.

Species: L. epidendrum, L. irregulare, L. maculatum, L. olivaceum.

Lycogala sect.

Oleogala Leontyev, Yatsiuk & Schnittler, sect. nov. MB 857822.

Etymology: Oleum (Latin), oil, and gala (Greek), milk, referring to the presence of oil in peridial vesicles and the attribution of the section to the genus Lycogala.

Diagnosis: Section unites species with peridial vesicles filled with considerable amount of oil.

Description: Sporocarps of different size, solitary or grouped, and in this case often deformed from mutual pressure. Vesicle pattern on the peridium distinct under RL, if not covered with patches of dried slime (L. flavofuscum); light or dark brown. Vesicles under TL densely distributed, solitary (L. olearium, L. fuscoolearium) or forming small compact rows and clusters with typically < 10 vesicles in one group. Oil in vesicles abundant, at least partially represented by conspicuous droplets, colourless, reddish or brownish. Crystals in vesicles absent or occasional (L. fuscoolearium). Rings or at least large, rounded pits present in ornamentation of capillitium and peridium. Fresh spore mass coloured in pale colours: beige, dull pinkish.

Typus: Lycogala olearium Leontyev, et al.

Species: L. confusum, L. densum, L. flavofuscum, L. fossiculatum, L. fuscoolearium, L. inconspicuum, L. olearium, L. sigillatum, L. skovorodaense.

Lycogala sect.

Tessellogala Leontyev, Yatsiuk & Schnittler, sect. nov. MB 857823.

Etymology: Tesselatus (Latin), decorated with a mosaic, and gala (Greek), milk, referring to the aggregated vesicles and the attribution of the section to the genus Lycogala.

Diagnosis: Section unites species with peridial vesicles forming large aggregates.

Description: Sporocarps small, scattered or grouped, more-or-less rounded in shape. Vesicle pattern on the peridium distinct, or faint (L. laeve) under RL, usually dark brown to black. Vesicles under TL densely distributed, forming large aggregates typically > 10 vesicles in one group; aggregates rounded, ovoid, rosette-shaped, papillate, or forming irregular reticulum. Oil in vesicles present, in form of granular material or droplets, colourless, brownish, or orange (L. paraconfusum, L. rubrosporum, L. squamatum). Crystals in vesicles absent or very scanty (L. aggregantum). Capillitium ornamented with small pits. Fresh spore mass beige, dull pinkish, or orange red (L. rubrosporum).

Typus: Lycogala exiguum Morgan

Species: L. echinocarpum, L. exiguum, L. laeve, L. microcarpum, L. paraconfusum, L. rubrosporum, L. squamatum, L. ustulatum.

Lycogala sect.

Tinctogala Leontyev, Yatsiuk & Schnittler, sect. nov. MB 857824.

Etymology: Tincto (Latin), to dye, and gala (Greek), milk, referring to the bright pigmentation of sporocarps and spores, and the attribution of the section to the genus Lycogala.

Diagnosis: Section unites species with solitary or fused, but not aggregated peridial vesicles, and with bright pigmentation of immature fructification and spore mass.

Description: Sporocarps small or medium in size, scattered or grouped, rounded, egg-shaped, fusiform, conical. Pinkish, lilac or umber tint often present in the pigmentation of mature sporocarps. Vesicles under RL distinct, dark brown to black, with glossy or at least smooth surface. Vesicles in TL solitary, more-or-less uniform in size, isodiametric, or branched (L. sphaeroconicum) and even fused into the network (L. conicium). Oil in vesicles nearly absent, or present as inconspicuous granular matter, rarely in form of red droplets (L. persicum). Crystals in vesicles absent. Capillitium ornamented with small pits. Fresh spore mass saturated pink (L. roseosporum, L. persicum), blue, fading to green (L. alisaulianovae), beige (L. umbrinum).

Typus: Lycogala roseosporum Leontyev, et al.

Species: Includes L. alisaulianovae, L. conicum, L. persicum, L. roseosporum, L. sphaeroconicum, L. umbrinum.

Lycogala sect.

Crystallogala Leontyev, Yatsiuk & Schnittler, sect. nov. MB 857825.

Etymology: Crystallus (Latin), crystal, and gala (Greek), milk, referring to the presence of crystals in peridial vesicles and the attribution of the section to the genus Lycogala.

Diagnosis: Section unites species with solitary peridial vesicles, regularly rounded in shape, uniform in size, evenly distributed, filled with crystals and/or yellow oily accumulations.

Description: Sporocarps medium in size to large, grouped, more-or-less rounded in shape. Vesicles under RL distinct, looking like dried droplets, evenly distributed, brown, honey yellow, orange or red. Vesicles under TL solitary, rounded or irregular (L. australe) in shape, filled with homogenous material. Crystals in vesicles present in considerable amount (visible under PL), rarely inconspicuous, and in this case yellow oil accumulations become visible (L. australe, L. guttatum, L. melleum, L. miserum). Orange pigment, not included in oil droplets, may be present in vesicles (L. caviaroides). Capillitium ornamented with bracelets. Fresh spore mass light-coloured: pinkish white, warm grey, beige.

Typus: Lycogala leopardinum Leontyev, et al.

Species: L. acinonychum, L. australe, L. caviaroides, L. costaricanum, L. guttatum, L. leopardinum, L. melleum, L. miserum, L. oleocrystalliferum, L. palianytsia, L. succineum.

Lycogala sect.

incertae sedis: L. asperum, L. botrydium, L. oncoides, L. pulchellum.

Lycogala persicum

Leontyev, J. Kluša, E. Moroz, Millican & Ishchenko, sp. nov. MB 857826. Fig. 5.

Etymology: Prunus persica (Latin) peach, referring to the colour of the peridium.

Diagnosis: Similar to L. roseosporum but differs by much larger colonies, smaller sporocarps, sparser peridial vesicles, and red oil accumulations in vesicles.

Sporocarps in large, scattered groups, spherical to short horizontally ovoid, regular in shape, (0.5–)1–2.5(–3.5) mm diam. Peridium membranous, light reddish brown, covered by vesicles. Peridial vesicles (40–)90–150(–230) µm, in RL brown to black, solitary, convex, somewhat unevenly distributed, free or forming loose groups, in TL simple, ovoid or angular, brown. Vesicle walls light-brown, thin (1 µm), 1–2-layered. Crystals absent. Oil droplets numerous, from large to small, more-or-less rounded, saturated red. Granular deposits, if present, represented by small oil droplets. Inner surface of the peridium smooth or covered by rings 1–2 µm diam. Capillitium tubular, 4–9 µm diam., with smooth contour; surface fine pitted-warty. Spore mass bright pink. Spores (5.5–)6.5–7.5 µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area occupies 1/4–1/5 of the spore surface. Immature fructifications bright pink, then light lilac.

Typus: Latvia, Pierīga, Jurmala, forest south of Kemeri, Kemeri National Park, (56.93383 23.49452), on a log of Picea abies, bare of bark, overgrown with moss, algae, and lichens, 1 Jul. 2023, J. Kluša (holotype GFW JuKl01). GenBank: nucSSU = PQ633803 (rg35).

Distribution: Europe (Belarus, Latvia, Russia), North America (Canada, USA). Hereinafter, refer to Table S1 for additional materials examined.

Notes: This beautiful myxomycete forms large colonies, which is quite unusual for Lycogala species with small (> 2 mm) sporocarps. In their young state, the sporocarps of L. persicum exhibit an exceptionally bright“chemical” pink colour, surpassing in intensity all other members of the genus. Based on the geographic distribution of records, the species seems to be associated with the boreal forest zone. From the related and similar L. roseosporum, L. persicum differs by the traits specified in the diagnosis.

Lycogala pulchellum

Leontyev, Ishchenko, M. Inoue & V. Botyakov, sp. nov. MB 857827. Fig. 6.

Etymology: Pulchellus (Latin) pretty, charming.

Diagnosis: Differs from the rest of Lycogala species by small single light yellow sporocarps, densely covered with dark solitary peridial vesicles, the surface of which possesses the ‘chain-mail’ ornamentation.

Sporocarps solitary, spherical, regular in shape, 2–2.5 mm diam. Peridium membranous, yellowish brown, covered by vesicles. Peridial vesicles (60–)90−130(–180) µm, in RL dark brown, solitary, folded, free or forming loose groups, which sometimes merge into irregular network, in TL simple, ovoid or blot-shaped, brown. Vesicle walls brown, thin (1–2 µm), 1–layered, covered with ‘chain-mail’ ornamentation, which consists of densely arranged rings 5–10 µm diam. Crystals absent. Oil droplets sparse, from large to small, variable in shape, colourless. Granular deposits not observed. Inner surface of the peridium smooth. Capillitium tubular, 3–11 µm diam., with smooth or slightly uneven contour; surface fine pitted-warty, with occasional ring-shaped islets. Spore mass light beige to dirty white. Spores (5–)5.5–7.5 µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area inconspicuous, represented by zone with larger meshes (2–4 across diam.). Immature fructifications light orange.

Typus: Ukraine, Ivano-Frankivsk Region, Halytskyi National Nature Park (49.0915 24.7175), on dead wood of Fagus sylvatica, 17 Aug 2010, D. Leontyev (holotype CWP2560). GenBank: nucSSU = OM423823 (rg34).

Distribution: Asia (Japan), Europe (Russia, Ukraine).

Notes: Species of the genus Lycogala with small solitary sporocarps are difficult to study: both their size and abundance present obvious challenges. However, among these species, L. pulchellum stands out for its unusual appearance and, when well-preserved, can be identified even without dissection. The contrast between the bright yellow peridium and large dark brown vesicles, along with the absence of coloured oil droplets and crystalline deposits, distinguishes L. pulchellum from L. inconspicuum and L. asperum. The presence of simple vesicles ornamented with a ‘chain-mail’ pattern differs it from L. exiguum, L. rubrosporum, and L. microcarpum.

Lycogala sphaeroconicum

Leontyev, E. Moroz, Ishchenko, E. Johannesen, Schnittler, T. Kudryavtseva & Bortnikov, sp. nov. MB 857828. Fig. 7.

Etymology: Sphaera (Greek) ball, globe, and conus (Latin) cone, referring to the similarity to L. conicum, yet with more spherical sporocarps.

Diagnosis: Differs from L. conicum by egg-shaped, blunt spindle-shaped, to almost spherical sporocarps and by shorter peridial vesicles, which do not from a regular reticulum.

Sporocarps in large and rather dense groups, vertically elongated, ovoid, egg-shaped, fusiform, spherical, (1–)2–2.5 mm high, 1–1.5 mm diam. Peridium membranous, light greyish brown, densely covered by vesicles. Peridial vesicles (20–)50–80(–90) µm wide, (50–)100–300(–600) µm long, in RL glossy, black, brownish black, solitary, flattened, with thickened edges, forming a kind of labyrinth, in TL simple, elongate, worm-like, branched, often touching each other but not merging into regular reticulum, brown. Vesicle walls light brown, thin (1 µm), 1–2-layered. Crystals absent. Oil present in form of granular deposits, colourless. Inner surface of the peridium smooth. Capillitium tubular, 1–2(–3) µm diam., with smooth contour; surface fine pitted-warty or completely smooth, occasionally with large (2–4 µm) ring-shaped islets, which may exceed the diameter of the tube. Spore mass warm greyish. Spores 5.5–6(–7) µm diam., hyaline, reticulate, 7–9 meshes across diam., unornamented area occupies 1/4–1/5 of the spore surface. Immature fructifications bright red.

Typus: Russia, Moskovskaya Oblast: Dmitrov, Buharovo (56.08929 37.28996), on the fallen rotting tree trunk, 21 Jul. 2021, T. Kudryavtseva (holotype GFW IY054). GenBank: nucSSU = PQ633706 (rg64); mtSSU = PQ633457.

Distribution: Europe (Belarus, Germany, Norway, Russia).

Notes: This species is related to and similar to L. conicum (Fig. 8), sharing its highly elongated and branched peridial vesicles. However, in collections, it is often labelled as L. exiguum because of its nearly spherical sporocarps. The covering of the fruiting bodies with black, glossy spots further enhances its superficial resemblance to L. exiguum. However, these peridial spots are individual vesicles and not vesicle aggregates, as seen in L. exiguum and its related species.

Lycogala umbrinum

Leontyev, P. Vetlesen, Schnittler, E. Moroz & E. Johannesen, sp. nov. MB 857829. Fig. 9.

Etymology: Umbra (Latin) shadow, referring to the colouration of sporocarps.

Diagnosis: Differs from L. alisaulianovae by the beige spore mass.

Sporocarps in small dense groups, spherical to short horizontally ovoid, regular in shape or slightly deformed from mutual pressure, (1.5–)2.5–5(–6) mm diam. Peridium membranous, dark lilac-brown, umber-brown, dull brown, covered by vesicles. Peridial vesicles (60–)120–190(–230) µm, in RL dark brown to black, solitary, convex, forming loose groups, merging into very fragmented reticulum, in TL simple, ovoid or blot-shaped, brown. Vesicle walls mainly brown, of medium thickness (2 µm), 1–2-layered. Crystals absent. Oil present in form of granular deposits, brownish. Inner surface of the peridium smooth, covered by scattered warts or rings 0.5–1 µm diam. Capillitium tubular, 3–7 µm diam., with smooth contour and fine pitted-warty surface, or less regular, with wavy contour and smooth surface, covered with occasional warts and rings. Spore mass beige. Spores (6–)6.5–8(–8.5) µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area occupies 1/3–1/4 of the spore surface. Immature fructifications unknown.

Typus: Germany, Bavaria, Bavarian Forest, Rachel, Transect 2, 6.9 km ESE to Frauenau (48.95264 13.37807), on strongly decayed and decorticated log of Abies alba, 3 Oct. 2013, M. Schnittler (holotype GFW sc27827). GenBank: nucSSU = OM424003 (rg36).

Distribution: Europe (Belarus, Germany, Norway).

Notes: A challenging species to identify, L. umbrinum resembles several taxa with solitary dark vesicles lacking crystals. The related species L. alisaulianovae differs from L. umbrinum by its bluish spore mass and looser arrangement of vesicles. The similar but unrelated L. maculatum is distinguished by its significantly darker, sometimes even black peridium without an umber hue and capillitium with pronounced warty bracelets. Another very similar species, L. ustulatum, has round thick-walled vesicles with a raised centre and flat periphery, and darker sporocarps without an umber hue.

Lycogala ustulatum

Leontyev, Ishchenko & Schnittler, sp. nov. MB 857830. Fig. 10.

Etymology: Ustulo (Latin) to scorch, to burn slightly, referring to the colour of sporocarps.

Diagnosis: Differs from L. umbrinum by dark brown sporocarps densely covered with rounded, very thick-walled vesicles, that have a raised centre and a flat periphery, and by presence of small, aggregated vesicles, which surround bigger ones.

Sporocarps mainly solitary, spherical to short horizontally ovoid, more-or-less regular in shape, (2–)3.5–5(–7.5) mm diam. Peridium membranous, reddish brown, covered by vesicles so densely, that sporocarp looks dark brown. Peridial vesicles or two types, large and small. Large vesicles (70–)110–170(–230) µm, in RL deep brown, solitary, flattened, but with a convex centre, densely and evenly distributed, in TL simple, rounded, ovoid, blot-shaped, brown. Large vesicle walls brown, very thick (5–20 µm), 1–2-layered, with the granular outer layer. Small vesicles rather inconspicuous, (20–)30–50(–70) µm diam., in TL aggregated, angular, thin-walled (1–2 µm), forming spots or irregular network around large vesicles. Crystals absent. Oil in both types of vesicles represented by granular deposits, abundant, brown. Inner surface of the peridium smooth or covered by warts. Capillitium tubular, 2–6 µm diam., with wavy contour; surface fine pitted-warty, with ring-shaped islets. Spore mass pinkish grey. Spores (6.5–)7–8 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area occupies 1/3–1/4 of the spore surface. Immature fructifications orange pink.

Typus: Russia, Moskovskaya Oblast, Moscow, North-Eastern Administrative District, Severnyi (55.92853 37.5545), on rotting wooden building material (boards), 20 Jun. 2022, Y. Ishchenko (holotype GFW IY094). GenBank: nucSSU = PQ633746 (rg42); mtSSU = PQ633469; COI = PQ628478.

Distribution: Asia (Japan), Europe (Russia).

Notes: This species, apparently common in the boreal zone of Eurasia, is rather difficult to identify. As noted in the diagnosis, it is similar to L. umbrinum, which, however, has uniformly convex vesicles, and a lilac hue of the peridium under RL. Another similar species, L. maculatum, has the capillitium with pronounced warty bracelets, the dark pigmentation of peridium between the vesicles, and often forms rosette-like clusters of sporocarps. Thick-walled vesicles with a raised centre and flat periphery mentioned in the diagnosis appear to be a fairly stable characteristic of L. ustulatum.

Lycogala olivaceum

Leontyev, Ishchenko & Gmoshinskiy, sp. nov. MB 857831. Fig. 11.

Etymology: Oliva (Latin) olive, referring to the colour of sporocarps.

Diagnosis: Differs from other Lycogala species by the greenish tint in the colouration of mature sporocarps and very large spores (8.5–9.5 µm diam.).

Sporocarps solitary or in small groups, spherical to horizontally ovoid, more-or-less regular in shape, (3–)3.5–5(–9.5) mm diam. Peridium membranous, light greenish or yellowish brown, covered by dark vesicles and abundant silvery patches of dried slime. Peridial vesicles (60–)80–120(–140) µm, in RL brown, solitary, folded, forming irregular chains, in TL simple, irregularly ovoid, light brown. Vesicle walls light-brownish, medium to thick (2–7 µm), 1–2-layered, with the granular outer layer. Crystals absent. Oil droplets scanty, granular deposits rather numerous, brownish. Inner surface of the peridium densely covered by warts. Capillitium tubular, 5–15 µm diam., with wavy contour; surface fine pitted-warty, with ring-shaped islets. Spore mass light pinkish. Spores (8–)8.5–9.5 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area indistinct, occupies 1/3–1/4 of the spore surface. Immature fructifications dull pink.

Typus: Russia, Moskovskaya Oblast, Gzhel, Kuzyaevo (55.62269 38.55919), on rotting trunk of Picea abies, on bare wood, on or near mosses, mainly Ptilidium pulcherrimum and Lophocolea heterophylla, as well as near lichens (Cladonia sp.), 13 Jul. 2020, Y. Ishchenko (holotype GFW IY043). GenBank: nucSSU = OM423951 (rg29).

Distribution: Europe (Russia).

Notes: The greenish colouration of the fruiting bodies fades with prolonged storage, complicating the identification of the species. Faded specimens, with their large size and peridium texture, resemble L. epidendrum s. str. Nonetheless, these two species can be distinguished by the texture of the capillitium: in L. epidendrum, the bracelets are densely ornamented with warty projections, whereas in L. olivaceum, warts are scanty. Additionally, the specimens of L. olivaceum we studied have very large spores (one of two biggest in the genus, together with L. maculatum), but more data are needed to evaluate the significance of this characteristic.

Lycogala laeve

Leontyev, Schnittler & E. Johannesen, sp. nov. MB 857832. Fig. 12.

Etymology: Laevis (Latin) smooth, smoothed, referring to the appearance of sporocarps and capillitium.

Diagnosis: Differs from L. epidendrum by smooth capillitium tubes, bare of warts, and by clustered vesicles, filled with dense granular material.

Sporocarps in small tight groups, spherical to short horizontally ovoid, rather regular in shape, (2–)3–5.5(–8) mm diam. Peridium membranous, light greyish brown, covered by somewhat darker vesicles and silvery patches of dried slime. Peridial vesicles (20–)30–70(–110) µm, in RL dull brown, slightly convex to nearly smooth, forming vague marble-like or reticulate pattern, in TL loosely aggregated, with 2–3 vesicles across the group, rounded-angular from mutual pressure, light brownish. Vesicle walls light-brownish, medium to thick (2–8 µm), 1–2-layered, with the granular layer covering the whole group. Crystals absent. Oil present in form of granular deposits, brown, reddish brown. Inner surface of the peridium densely covered by warts. Capillitium tubular, 6–20 µm diam., with wavy contour and smooth surface, ornamented with only occasional warts or rings. Spore mass warm grey. Spores (6–)6.5–8.5 µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area indistinct, 1/4–1/5 of the spore surface. Immature fructifications unknown.

Typus: Germany, Bavaria, lower montane forest near Garmisch-Partenkirchen, ca 600 m south of the Kainzenbad (47.47922 11.12411), on dead wood of Picea abies, ca 850 m a.s.l., 4 Jun. 2023, D. Leontyev (holotype CWP4644). GenBank: nucSSU = PQ633672 (rg43).

Distribution: Europe (Germany, Norway).

Notes: This species is a twin of L. epidendrum, sharing its large size, poorly defined texture, and silvery-brown colouration of sporocarps. The morphological distinction between L. laeve and L. epidendrum is rather problematic. However, as stated in the diagnosis, the new species has smooth capillitium tubes, almost devoid of warts (as observed under LM), whereas in L. epidendrum they are adorned with large warts. The peridial vesicles of L. laeve form a loose network of rows and clusters, while in L. epidendrum, they are barely grouped. L. laeve also appears less inclined to form large colonies, which is very typical of L. epidendrum. By its marble-like pattern, the peridium of L. laeve resembles that of L. confusum, but the latter lacks accumulations of dried slime and, as a result, does not exhibit a silvery hue. The new species seems to prefer cold habitats, as it has been found in Norway and the Bavarian Alps.

Lycogala paraconfusum

Leontyev, Ishchenko & V. Dzizurova, sp. nov. MB 857833. Fig. 13.

Etymology: Para (Greek) near, beside, or para (Latin) protection against, and confusus (Latin) mixed, confused, referring to the similarity to L. confusum.

Diagnosis: Differs from L. confusum by the absence of marble-like reticulate pattern of the peridium and regular rounded shape of sporocarps.

Sporocarps in small tight groups and rows, spherical to short horizontally ovoid, often deformed from mutual pressure, (2.5–)4–5.5(–7.5) mm diam. Peridium membranous, light brown, covered by vesicles. Peridial vesicles (10–)30–60(–130) µm, in RL brown, folded, often with central depression, forming rather dense reticulate pattern, in TL aggregated, with 2–3 vesicles across the group, rounded-angular from mutual pressure, light brownish. Vesicle walls nearly colourless, multilayered, with the inner layer 1–3 µm thick, smooth, and rather indistinct outer layers 5–15 µm thick, granular, covering the whole group of vesicles. Crystals absent. Oil present in form of granular deposits, brown or orange red. Inner surface of the peridium covered by warts. Capillitium tubular, 3–10 µm diam., with smooth or wavy contour; surface fine pitted-warty, with occasional ring-shaped islets. Spore mass light pinkish. Spores 7–8.5(–9) µm diam., hyaline, reticulate, 5–8 meshes across diam., unornamented area indistinct, 1/4–1/5 of the spore surface. Immature fructifications pinkish orange.

Typus: Russia, Primorsky Krai, Ussuriysky State Reserve, Komarovka valley (43.64827 132.37017), on rotten wood, 18 Aug. 2022, V. Dzizurova (holotype GFW IY119). GenBank: nucSSU = PQ633772 (rg14); COI = PQ628497.

Distribution: Asia (Russia), Europe (Germany, Russia).

Notes: This species closely resembles L. confusum when examining the details of the peridium under RL and TL. This similarity is quite remarkable, considering that L. confusum and L. paraconfusum are not closely related. However, the overall appearance of the sporocarps allows these species to be distinguished even without dissection. L. confusum has irregularly shaped fruiting bodies, with vesicles on their surface forming a distinctive “marbled” pattern (Leontyev et al. 2023). In contrast, the sporocarps of L. paraconfusum are predominantly regular in shape, and their vesicles form a network of isolated spots. In L. confusum, we also observed pronounced differentiation in the ornamentation of the capillitium, with regularly spaced with ring-shaped islets, which are absent in L. paraconfusum. In L. paraconfusum, but not in L. confusum, oil accumulations in the peridium exhibit a reddish colouration. However, the last two traits require further study based upon a broader sampling.

Lycogala nigroconfusum

Leontyev, W.-L. Song, Shuang L. Chen & S.L. Stephenson, sp. nov. MB 857834. Fig. 14.

Etymology: Niger (Latin) black, and confusum (Latin) confusing referring to the dark pigmentation of peridial vesicles and the similarity to L. confusum and L. paraconfusum.

Diagnosis: Differs from L. confusum and L. paraconfusum by the very dark peridial vesicles with multilayer walls.

Sporocarps solitary or in small groups, spherical to short horizontally ovoid, mostly regular in shape, (4–)4.5–6(–7.5) mm diam. Peridium membranous, light brown, covered by vesicles so densely, that sporocarp looks black. Peridial vesicles (10–)40–70(–80) µm, in RL black, forming dense reticulate pattern on the peridium, convex, matt, in TL aggregated in rows, rings or clusters, with 1–3 vesicles across the group, rounded or rounded-angular from mutual pressure, dark brown. Vesicle walls dark brown, multilayered, with the inner layer 2–3 µm thick, smooth, and the outer layers 5–20 µm thick, granular, covering the whole group of vesicles. Crystals absent. Oil droplets numerous, large, colourless (rg13) or orange red (rg45). Inner surface of the peridium smooth or covered by scanty warts and rings. Capillitium tubular, 4–10 µm diam., with wavy contour; surface fine pitted-warty, with ring-shaped islets. Spore mass beige. Spores (6–)6.5–7 µm diam., hyaline, reticulate, 5–6 meshes across diam., unornamented area occupies 1/4–1/5 of the spore surface. Immature fructifications unknown.

Typus: USA, Tennessee, Long Hunter State Park, cedar and hardwood forest (36.1173–86.5660), on dead wood, 16 Aug. 2006, W.C. Rosing (holotype UARK36077). GenBank: nucSSU = OM424041 (rg13).

Distribution: Asia (China), North America (USA).

Notes: By the naked eye L. nigroconfusum resembles other species with nearly black fructifications (L. maculatum and L. squamatum) but differs from both by the mutual arrangement of peridial vesicles (which are free or clustered in rosettes, respectively, in two abovementioned species). A tendency to form rows of vesicles puts L. nigroconfusum together with L. confusum, L. paraconfusum and L. fossiculatum, but all these species have much lighter vesicle walls. Another similar species, L. sigillatum possesses vesicles resembling dried droplets, which, despite their dense arrangement, do not form a reticulum.

Lycogala inconspicuum

Leontyev, Ishchenko, Schnittler & E. Johannesen, sp. nov. MB 857835. Fig. 15.

Etymology: Inconspicuus (Latin) invisible, indiscernible, referring to the small size and poor ornamentation of sporocarps.

Diagnosis: Differs from the rest of Lycogala species by the combination of small solitary sporocarps and small elongate peridial vesicles which form linear chains and contain reddish oil and scanty crystal druses.

Sporocarps solitary, spherical to short horizontally ovoid, often somewhat irregular in shape, (2–)2.5–3(–3.5) mm diam. Peridium membranous, light brown, covered by vesicles. Peridial vesicles (30–)50–90(–170) µm, in RL brown, dark brown, folded, forming loose reticulate pattern, in TL aggregated, with 1–2 vesicles across the group, elongate, with thinner “tails”, often angular from mutual pressure, light brownish. Vesicle walls light-brownish, thin (1 µm), single-layered. Crystals present as small dense clusters, not filling the whole vesicle. Oil present in form of small droplets and granular deposits, brown or orange red. Inner surface of the peridium smooth or covered by warts. Capillitium tubular, 3–10 µm diam., with wavy contour; surface fine pitted-warty, with occasional ring-shaped islets. Spore mass beige. Spores (6–)6.5–7.5 µm diam., hyaline, reticulate, 7–9 meshes across diam., unornamented area 1/3–1/2 of the spore surface. Immature fructifications pink.

Typus: Germany, Mecklenburg-Vorpommern, Western Pomerania, Greifswald, small hedge around fields 1.5 km W Dersekow (54.04568 13.26444), on a strongly decayed log of Fraxinus excelsior, diam. 45 cm, 20 Jul. 2011, M. Schnittler (holotype GFW sc22097). GenBank: nucSSU = OM423968 (rg03); mtSSU = PQ633586.

Distribution: Europe (Germany, Norway, Russia).

Notes: Small solitary sporocarps with an indistinct vesicle pattern associate this species with L. miserum and L. asperum. Both of these differ from L. inconspicuum by their solitary vesicles, filled with yellow oil droplets, as well as by abundant crystalline deposits (L. miserum) and ring-like ornamentation of the peridium (L. asperum).

Lycogala echinocarpum

Leontyev, Ishchenko & Bortnikov, sp. nov. MB 857836. Fig. 16.

Etymology: Echinos (Greek) sea urchin, and carpon (Greek) fruit, referring to the general appearance of sporocarps.

Diagnosis: Differs from the rest of Lycogala species by papillate projections on the sporocarp surface, formed by aggregated vesicles enclosed in thick covers.

Sporocarps in small groups, spherical to short horizontally ovoid, more-or-less regular in shape, (3–)4.5–5.5(–6.5) mm diam. Peridium membranous, light brown, covered by vesicles so densely, that sporocarp looks black. Peridial vesicles in aggregates that look like prominent papillate protrusions, giving the sporocarps a spiny appearance, black, glossy, forming dense, stellate or dotted pattern at the surface of sporocarp; in TL aggregates (80–)130–170(–220) µm diam. rounded, forming a dense network of moniliform rows, with 4–7 vesicles across the group. Individual vesicles (10–)20–40(–50) µm, angular from mutual pressure, dark brown. Vesicle walls brown, multi-layered, very thick-walled (12–25 μm), with the granular outer layer, covering the whole group. Crystals absent. Oil present in form of granular deposits, brown. Inner surface of the peridium smooth. Capillitium tubular, 8–20 µm diam., with wavy contour; surface fine pitted-warty or almost smooth, with occasional ring-shaped islets or rather well-developed rings. Spore mass beige. Spores (6–)6.5–7 µm diam., hyaline, reticulate, 7–9 meshes across diam., unornamented area indistinct, 1/4–1/5 of the spore surface. Immature fructifications pink, then reddish brown, with vesicles darker than the background.

Typus: Russia, Moskovskaya Oblast, Moscow, North-Eastern Administrative District, Severnyi (55.92839 37.55094), on deciduous tree logs, on bare wood, on and near the moss Amblytegium sp., 18 Jun. 2020, Y. Ishchenko (holotype GFW IY038). GenBank: nucSSU = OM423946 (rg25).

Distribution: Europe (Russia).

Notes: Noticeable papillate projections on the peridium, formed by aggregated vesicles, distinguish this species from any other Lycogala. Similar species with dark sporocarps (L. maculatum, L. ustulatum) have solitary and much flatter vesicles.

Lycogala rubrosporum

Leontyev, W.-L. Song, Shuang L. Chen, Y. Yamamoto & Schnittler, sp. nov. MB 857837. Fig. 17.

Etymology: Ruber (Latin) red, and spora (Greek), seed, referring to the colour of the fresh spore mass.

Diagnosis: Differs from the rest of Lycogala species by combination of saturated brick red spore mass and rosette shape of vesicle aggregates.

Sporocarps scattered, spherical, regular in shape, 2–3.5(–4) mm diam. Peridium membranous, light reddish brown, covered by vesicles so densely, that sporocarp looks dark brown to black. Peridial vesicles in aggregates that look like black spots of rosette shape and pitted surface, separated from each other by a regular thin network of vesicle-lacking areas; in TL aggregates 220–300(–500) µm diam., dense, petaloid, with 5–7 vesicles across the group. Individual vesicles (30–)50–90(–130) µm, rounded, somewhat angular from mutual pressure, dark brown. Vesicle walls thin (1–2 µm), 1–2-layered, with inconspicuous outer layer covering the whole group. Crystals occasional or absent. Oil droplets numerous, from large to small, and in the form of granular deposits, orange-red, orange yellow, brownish. Inner surface of the peridium smooth or covered by scanty warts. Capillitium tubular, 2–10 µm diam., with wavy contour; surface fine pitted-warty, with ring-shaped islets. Spore mass bright orange red. Spores (5.5–)6–7 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area occupies 1/3–1/4 of the spore surface. Immature fructifications unknown.

Typus: China, Hubei Province, Houhe National Nature Reserve (47.757 133.695), on strongly decayed wood, 22 Jul. 2019, M. Li, X. Tao & B. Li (holotype MCCNNU3695). GenBank: nucSSU = ON920628 (rg53); mtSSU = PQ633513.

Distribution: Asia (China, Japan, South Korea, Vietnam).

Notes: This species is related to L. aggregatum and L. squamatum, sharing with them the rosette-shaped vesicle aggregates. However, the bright, brick-red colouration of the spore mass distinguishes L. rubrosporum not only from related taxa, but also from all other described species of the genus. When the spore mass of L. rubrosporum fades, it may resemble L. squamatum, but in the latter, the lines between the rosettes are usually darker in colour.

Lycogala squamatum

Leontyev, Y. Bengus & Bortnikov, sp. nov. MB 857838. Fig. 18.

Etymology: Squama (Latin) scale, referring to the general appearance of sporocarps.

Diagnosis: Differs from L. aggregatum by darker and more regular lines between rosette-shaped vesicle aggregates, and by red oil droplets deposited in vesicles.

Sporocarps scattered, spherical to short horizontally ovoid, more-or-less regular in shape, (1.5–)2.5–3.3(–6.0) mm diam. Peridium membranous, dark brown, covered by vesicles so densely, that sporocarp looks entirely black. Peridial vesicles in aggregates that look like black spots of rosette shape and pitted surface, separated from each other by a regular thin network of vesicle-lacking areas; in TL aggregates (220–)250–310(–440) µm diam., dense, petaloid, with 2–7 vesicles across the group. Individual vesicles (40–)60–110(–160) µm, rounded, somewhat angular from mutual pressure, dark brown. Vesicle walls thin to medium (1–3 µm), 1–2-layered, with inconspicuous outer layer covering the whole group. Crystals occasional or absent. Oil droplets numerous, from large to small, and in the form of granular deposits, orange red. Inner surface of the peridium smooth or covered by warts and rings. Capillitium tubular, 3–10 µm diam., with wavy contour; surface fine pitted-warty, with ring-shaped islets or rather well-developed rings. Spore mass beige. Spores (5.5–)6–7 µm diam., hyaline, reticulate, 5–8 meshes across diam., unornamented area nearly absent or occupies 1/4–1/5 of the spore surface. Immature fructifications unknown.

Typus: Ukraine, Kharkiv Region, Kharkiv, Nova Bavaria (49.949313 36.18936), on the dead wood of Acer negundo, 4 Jul. 2020, Y.V. Bengus (holotype CWP4233). GenBank: nucSSU = OM423894 (rg31); COI = ON931560.

Distribution: Asia (Vietnam), Europe (Russia, Ukraine).

Notes: This taxon was described based on a complex of three phylogenetically close and morphologically similar putative biospecies (rg27, 31, 61); broader sampling in the future may allow these taxa to be separated. All members of the complex are characterized by dark fruiting bodies regularly paved with black spots, which represent rosette-like aggregates of vesicles. The dense arrangement of these aggregates gives the sporocarps a scaly appearance. Unlike L. rubrosporum and L. aggregatum, the spaces between the vesicles in L. squamatum are rather dark, and the vesicles themselves contain red oil droplets. The type specimen, representing rg31, is also distinguished by relatively large (up to 6 mm) and particularly darkly coloured fruiting bodies.

Lycogala microcarpum

Leontyev, Ishchenko, W.-L. Song & Shuang L. Chen, sp. nov. MB 857839. Fig. 19.

Etymology: Micros (Greek) small, and carpon (Greek) fruit, referring to the size of sporocarps.

Diagnosis: Differs from L. exiguum by the regular short ovoid shape of peridial vesicle aggregates, which do not form a unified network.

Sporocarps scattered, spherical, regular in shape, (0.5–)1–2.5(–3) mm diam. Peridium membranous, light reddish brown, covered by vesicles so densely, that sporocarp looks dark brown. Peridial vesicles in aggregates that look like dark brown to black spots of ovoid shape and pitted surface, separated from each other by a network of vesicle-lacking areas; in TL aggregates (20–)100–170(–220) µm diam., dense, ovoid, with 4–6 vesicles across the group. Individual vesicles (10–)30–40 µm, rounded, somewhat angular from mutual pressure, brown. Vesicle walls thin (1–2 µm), multi-layered, with smooth outer layer covering the whole group. Crystals absent. Oil droplets small or in the form of granular deposits, colourless or brownish. Inner surface of the peridium smooth or covered by scanty warts. Capillitium tubular, 2–10 µm diam., with slightly wavy contour; surface fine pitted-warty, with ring-shaped islets. Spore mass beige. Spores 5–6(–6.5) µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area occupies 1/3–1/4 of the spore surface. Immature fructifications bright orange.

Typus: Russia, Primorsky Krai, Ussuriysky State Reserve (43.6525 132.46581), on the trunk of a rotting fallen tree, 17 Aug. 2022, Y. Ishchenko (holotype GFW IY116). GenBank: nucSSU = PQ633769 (rg50); mtSSU = PQ633476; COI = PQ628494.

Distribution: Asia (Vietnam), Europe (Russia, Ukraine).

Notes: This species belongs to the L. exiguum complex (Fig. 30, see below), which requires further studies, as it includes at least eight hard-to-distinguish putative biospecies. However, L. microcarpum can be reliably differentiated from the rest of the group, and particularly from the type material of L. exiguum (Leontyev & Schnittler 2023) by the regular ovoid shape of its vesicle aggregates, which do not form a network on the surface of the sporocarp. The appearance of the fruiting bodies in this species is distinctive enough to allow identification without dissection.

Lycogala sigillatum

Leontyev, W.-L. Song & Shuang L. Chen. sp. nov. MB 857840. Fig. 20.

Etymology: Sigillum (Latin) stamp, referring to the similarity of peridial vesicles, as seen in RL, to the antique wax seal.

Diagnosis: Differs from L. skovorodaense by the light orange brown peridium, dark red brown vesicles and smooth capillitium threads.

Sporocarps solitary or in small groups, spherical to short horizontally ovoid, mostly regular in shape, (1.5–)2.5–5.5(–6.5) mm diam. Peridium membranous, light brown, densely covered by vesicles. Peridial vesicles (20–)40–80(–120) µm, in RL dark reddish brown, forming small irregular groups with pitted surface, in TL grouped in dense rounded clusters with 1–2 vesicles across the group, somewhat angular from mutual pressure, brown. Vesicle walls brown, thin to medium (1–2 µm), but looking thicker because the granular contents of the vesicle leave some free space around the wall; 1–2-layered. Crystals absent. Oil droplets numerous, small, variable in shape, colourless. Inner surface of the peridium smooth or covered by scanty warts and rings. Capillitium tubular, 2–15 µm diam., with wavy contour; surface fine pitted-warty, with ring-shaped islets. Spore mass beige. Spores (6–)6.5–7 µm diam., hyaline, reticulate, 5–6 meshes across diam., unornamented area occupies 1/3–1/4 of the spore surface. Immature fructifications unknown.

Typus: China, Guangdong Province, Dinghushan National Nature Reserve (23.1659 112.5409), on strongly decayed wood, 29 May 2014, B. Wei & G. He (holotype MCCNNU0796). GenBank: nucSSU = ON920615 (rg44).

Distribution: Asia (China).

Notes: This species resembles L. skovorodaense, although it is not closely related to it in terms of phylogeny. However, in the latter, the capillitium is covered with spine-like projections or at least with massive granulation, whereas in L. sigillatum, it is ornamented only with small pits and smooth bracelets. The new species also differs by pigmentation of the peridium and vesicles in RL: both structures are coloured in L. sigillatum much brighter, than in L. skovorodaense. From the superficially similar L. ustulatum and L. maculatum the new species differs by the grouping of vesicles into small, rounded aggregates.

Lycogala fuscoolearium

Leontyev, Ishchenko, T. Kudryavtseva & R. Skrzypczak, sp. nov. MB 857841. Fig. 21.

Etymology: Fuscus (Latin) swarthy, dusky, and olearius (Latin), oily, referring to the similarity to L. olearium, but with darker oil accumulations.

Diagnosis: Differs from L. olearium by dark fuscous oil accumulations, more conspicuous peridial vesicles, occasional presence of crystals, and equal size of the meshes of spore ornamentation.

Sporocarps grouped, spherical to short horizontally ovoid, often deformed from mutual pressure, dull brown, (1–)4.5–7.5(–10) mm diam. Peridium membranous, light brown, dark brown, covered by vesicles. Peridial vesicles (80–)110–150(–210) µm, in RL light brown, amber yellow, light orange, convex, solitary or loosely grouped, in TL simple, ovoid or angular, brownish. Vesicle walls under TL hyaline, very thin (1 µm), inconspicuous. Crystals usually absent, if present – form small to rather large dense clusters. Oil droplets numerous, large (30–80 μm) and small, dull yellowish brown, orange brown, sometimes dark brown in mass, or only in the form or brownish granular deposits. Inner surface of the peridium smooth, sometimes pitted or covered by scattered warts or regular rings 1–2 µm diam. Capillitium tubular, 6–15 µm diam., with smooth or wavy contour, with two main types of ornamentation: by rings on the smooth surface or by regular warty bracelet-like thickenings. Spore mass light pinkish beige. Spores (6–)6.5–8 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area occupies 1/2–1/3 of the spore surface. Immature fructifications light pinkish, with vesicles brighter than the background.

Typus: Russia, Moskovskaya Oblast, Volokolamsk, Litvinovo, Strizh (56.05156 36.19306), on decaying coniferous trunk, on rotten wood, on moss Jochenia pallescens and liverwort Lophocolea heterophylla, 12 Jun. 2020, Y. Ishchenko (holotype GFW IY019). GenBank: nucSSU = OM423930 (rg32); COI = ON931572.

Distribution: Europe (France, Russia).

Notes: This species is related to L. olearium, with which it shares many common features, including abundant oil accumulations in the peridial vesicles and ring-like ornamentation observed on the peridium and capillitium. The differences between these two species are specified in the diagnosis. Compared to another closely related species, L. densum, L. fuscoolearium differs by the sparser arrangement of vesicles and several other traits (see the diagnosis of L. densum). Due to its distinct vesicles, which may be yellowish or orange, L. fuscoolearium resembles ‘crystalliferous’ species, such as L. leopardinum, L. succineum, and L. caviaroides, but differs from them by the abundant presence of oil in the vesicles.

Lycogala densum

Leontyev, M. Kobayashi, E. Moroz, T. van der Heul, Bortnikov, E. Johannesen & Schnittler, sp. nov. MB 857842. Fig. 22.

Etymology: Densus (Latin) dense, overgrown, tightly closed, referring to the dense cover of peridial vesicles.

Diagnosis: Differs from L. fuscoolearium by the dense arrangement of peridial vesicles, their orange-brown colouration and convex shape, as well as by the light yellowish oil accumulations, and bigger (6–8 µm) spores.

Sporocarps scattered, spherical to short horizontally ovoid, more-or-less regular in shape, (1.5–)3.5–6(–8) mm diam. Peridium membranous, light orange-brown, densely covered by vesicles. Peridial vesicles (30–)80–120(–160) µm, in RL look like dried droplets, as light as the peridium or somewhat darker, yellowish to orange-brown, solitary, convex, distant from each other on 0.5–1 of their diam., in TL simple, ovoid, light yellow. Vesicle walls light brownish, thin (1–2 µm), 1–2-layered, with the outer layers more-or-less smooth. Crystals absent. Oil droplets numerous, large (30–50 µm) or only small, more-or-less rounded, yellowish or light brown. Inner surface of the peridium smooth or covered by warts and inconspicuous rings. Capillitium tubular, 5–15 µm diam., with smooth or wavy contour, ornamented by clustered warts or nearly smooth. Spore mass pinkish beige. Spores (5–)6–8 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area indistinct, occupies 1/4–1/5 of the spore surface. Immature fructifications unknown.

Typus: Japan, Honshu, Nagano, Lake Matsubara, Koumi-Chom Minami Saku-Gun (36.054 138.456), on dead wood, 25 Jun. 2005, M. Kobayashi & M. Kobayashi (holotype TNSM12581). GenBank: nucSSU = PQ633916 (rg86).

Distribution: Asia (Japan), Australia, Europe (Belarus, Norway, Russia).

Notes: This taxon was described based on a complex of three phylogenetically close and morphologically similar biological species (rg28, 86, 87); broader sampling may allow to separate these biospecies in future. All members of the complex are characterized by densely arranged convex vesicles coloured in orange-brown tone and containing numerous yellowish or brownish oil droplets. Dense and convex vesicle patterns abovementioned traits distinguish L. densum from the related L. fuscoolearium. Additionally, although we observed ring-like ornamentation of the peridium in L. densum, it appears to be less developed than in other oil-containing species, such as L. fuscoolearium and L. olearium. By its distinct rounded vesicles, L. densum resembles ‘crystalliferous’ species, especially L. acinonychum, but differs from them by abundant oil accumulations.

Lycogala oleocrystalliferum

Leontyev, Ishchenko, S.J. Lloyd ., W.-L. Song, Shuang L. Chen, Schnittler, V. Botyakov & E. Moroz, sp. nov. MB 857843. Fig. 23.

Etymology: Olearius (Latin), oily, and crystallifer (Latin), bearing crystals, referring to the presence of both oily and crystalline accumulations in peridial vesicles.

Diagnosis: Differs from L. olearium by more conspicuous peridial vesicles, often containing orange pigment, and from L. caviaroides by the presence of oil.

Sporocarps in tight groups, spherical to short horizontally ovoid, often deformed from mutual pressure, (1.5–)2.5–4(–6) mm diam. Peridium membranous, light orange-brown, covered by vesicles. Peridial vesicles (60–)80–120(–150) µm, in RL look like dried droplets, bright orange, orange-brown, brown, semitranslucent, solitary, convex or folded, evenly distributed, distant from each other on 0.5–2 of their diam., in TL simple, ovoid, brown. Vesicle walls colourless, thin (1 µm), single-layered. Crystals present, forming rounded aggregates, masked by the presence of oil. Oil in the form of granular deposits, brown, densely filling entire vesicle. Orange vesicles contain pigment accumulations of the same colour. Inner surface of the peridium smooth or covered by warts. Capillitium tubular, 3–15 µm diam., ornamented by regular warty bracelet-like thickenings; the depressions between the bracelets are ornamented with large ring-shaped pits. Spore mass light pinkish. Spores (6–)6.5–7.5 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area occupies 1/2–1/4 of the spore surface. Immature fructifications orange pink, with vesicles brighter than the background.

Typus: Russia, Moskovskaya Oblast, Moscow, North-Eastern Administrative District, Severnyi (55.92871 37.55439), on rotten wood, 3 Jul. 2023, Y. Ishchenko (holotype GFW IY154). GenBank: nucSSU = PQ633801 (rg51).

Distribution: Asia (China), Australia, Europe (Belarus, Russia).

Notes: This taxon was described based on a complex of three phylogenetically close and morphologically similar putative biological species (rg51, 72, 74); broader sampling may allow to separate these biospecies in future. All members of the complex are characterized by rounded solitary peridial vesicles, filled with brown granular oil and at the same time showing birefringence at polarized light, which indicates crystal accumulations. In RL the colour of these vesicles varies from bright orange to dull brown, resembling in the first case L. caviaroides, and in the second – L. succineum, L. palyanytsia, and L. fuscoolearium. Specimens with orange vesicles represent the only currently known “twin” species of L. caviaroides. Interestingly, L. oleoctystalliferum resembles this species also by the ornamentation of capillitium: the depressions between the bracelets are ornamented with large ring-shaped pits. This was observed in rg51, to which the species holotype belongs; in rg74 these structures are less prominent.

Lycogala guttatum

Leontyev, W.-L. Song, Shuang L. Chen, Ishchenko, D. Panayotova & V. Botyakov, sp. nov. MB 857844. Fig. 24.

Etymology: Gutta (Latin) droplet, referring to the presence of large yellow oil droplets in peridial vesicles.

Diagnosis: Differs from L. succineum by the presence of yellowish oil droplets and absence of crystals in peridial vesicles.

Sporocarps grouped, spherical to short horizontally ovoid, often deformed from mutual pressure, (2.5–)4–5.5(–7.5) mm diam. Peridium membranous, light yellowish brown, covered by vesicles. Peridial vesicles (70–)100–140(–280) µm, in RL look like dried droplets, light brown, solitary, convex or depressed in the central part, evenly distributed, distant from each other on 1–3 of their diam., in TL simple, ovoid, nearly hyaline. Vesicle walls colourless, thin (1 µm), single-layered. Crystals absent. Oil droplets large [20–50(–120) µm] and small, bright warm-yellow, very conspicuous on the hyaline background. Inner surface of the peridium covered by warts and rings. Capillitium tubular, 2–10 µm diam., with smooth or wavy contour and two main types of ornamentation: by regular, bracelet-like thickenings and by rings and pits. Spore mass light pinkish. Spores (6–)6.5–8.5(–9.5) µm diam., hyaline, reticulate, 4–6 meshes across diam., unornamented area occupies 1/2–1/3 of the spore surface. Immature fructifications light to bright pinkish orange, with vesicles brighter than the background.

Typus: USA, California, Scotts Valley, Henry Cowell Redwoods State Park (37.028339–122.04549), on dead wood, 14 Dec. 2019, D. Panayotova (holotype CWP3660). GenBank: nucSSU = OM423856 (rg15); mtSSU = PQ633412; COI = ON931546.

Distribution: Asia (China), Europe (Russia), North America (USA).

Notes: This taxon was described based on a complex of three phylogenetically close and morphologically similar biological species (rg15, 84, 91); broader sampling may allow to separate these biospecies in future. All members of the complex resemble L. succineum by their beige sporocarps, covered with accurate honey brown vesicles, rather distant from each other. Microscopic structures, like large oil droplets and ring ornamentation of capillitium, put L. guttatum together with oil-containing species, but the bright warm yellow pigmentation of oil distinguishes it from L. olearium and L. fuscoolearium. One more “oily” species, L. densum, has much denser and darker vesicles, and its oil pigmentation is only slightly yellowish. Two more species contain bright yellow oil: L. miserum and L. asperum, but both have small (3–3.5 and 2–3 mm, respectively) and solitary sporocarps. L. miserum, in addition, contains crystals, and L. asperum has convex dark brown vesicles, spiny capillitium and rings on peridium.

Lycogala melleum

Leontyev, W.-L. Song, Shuang L. Chen & M. Shim, sp. nov. MB 857845. Fig. 25.

Etymology: Mel (Latin) honey, referring to the colour of the fresh peridial vesicles.

Diagnosis: Differs from L. succineum by yellow pigmentation of immature sporocarps and almost absent crystal accumulations in peridial vesicles.

Sporocarps in small groups, spherical to short horizontally ovoid, regular in shape, (1.5–)2.5–3(–4.5) mm diam. Peridium membranous, light orange brown, covered by vesicles. Peridial vesicles (100–)120–170(–270) µm, in RL look like dried droplets, dull orange, orange-brown, brown, semitranslucent, solitary, convex, evenly distributed, distant from each other on 0.5–1 of their diam., in TL simple, ovoid, yellowish to brown. Vesicle walls light brownish, thin (1 µm), single-layered. Crystals very rare, in form of small inclusions. Oil inconspicuous. Amorphous pigment accumulations of yellow or orange colour present in most of vesicles. Inner surface of the peridium covered by warts and rings. Capillitium tubular, 6–20 µm diam., with smooth or wavy contour and two main types of ornamentation: by regular, bracelet-like thickenings and by rings and pits. Spore mass light yellowish beige. Spores (5.5–)6–7 µm diam., hyaline, reticulate, 4–5 meshes across diam., unornamented area occupies 1/2–1/3 of the spore surface. Immature fructifications yellow.

Typus: South Korea, Ulsan, Nam-gu district, Ulsan Grand Park (35.527053 129.295456), on a cone of Pinus densiflora, 17 Jun. 2022, K. Lee & M. Shim (holotype GFW MiShim01). GenBank: nucSSU = ON920625 (rg52); mtSSU = PQ633510.

Distribution: Asia (China, South Korea).

Notes: The bright yellow colouration of the sporocarps distinguishes L. melleum from all other described members of the genus. However, the authors have seen photographs of orange yellow sporocarps in L. epidendrum s. str., which typically has pink colouration, thus revealing possible within-species polymorphism of this character (see www.naturephoto-cz.com, accession 17205) For this reason, the stability of the colour characteristic within L. melleum requires further study. This species, however, can as well be reliably identified in its fully mature state. It resembles the related L. succineum, but it has slightly smaller sporocarps (2.5–3 mm) and, most important, its peridial vesicles contain virtually no crystals, whereas L. succineum is known for their abundant accumulation.

Lycogala costaricanum

Leontyev, Schnittler & C. Rojas, sp. nov. MB 857846. Fig. 26.

Etymology: Costa Rica, referring to the type locality.

Diagnosis: Differs from other ‘crystalliferous’ species like L. leopardinum and L. succineum by the greyish colour of sporocarps, their smaller size (1.5–2.5 mm) and remarkably verrucose capillitium.

Sporocarps grouped, spherical to short horizontally ovoid, regular in shape, (0.5–)1.5–2.5(–3.5) mm diam. Peridium membranous, warm grey, covered by vesicles. Peridial vesicles (60–)90–120(–170) µm, in RL look like dried droplets, dull brownish, semitranslucent, solitary, convex or folded, evenly distributed, distant from each other on 0.5–1 of their diam., in TL simple, irregularly ovoid, light brownish. Vesicle walls hyaline, thin (1 µm), single-layered. Crystals numerous, forming irregular aggregates, often completely filling the inner space of the vesicle. Oil present in form of granular accumulations, brownish. Inner surface of the peridium smooth, with occasional warts. Capillitium tubular, 3–10 µm diam., with wavy contour, ornamented by regular, bracelet-like thickenings, which are covered by numerous large warts, clearly visible under TL. Spore mass light warm grey. Spores (5–)6–6.5 µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area occupies 1/2–1/3 of the spore surface. Immature fructifications unknown.

Typus: Costa Rica, Cartago, Turrialba, FEIMA Experimental Forest, near village La Suiza (-83.63698 9.86589), on strongly decayed woody branch, 3 cm diam., 23 Feb. 2020, M. Schnittler (holotype GFW sc32114). GenBank: nucSSU = OM424026 (rg17); mtSSU = PQ633607; COI = ON931602.

Distribution: Central America (Costa Rica).

Notes: This is the only currently known representative of ‘crystalliferous’ Lycogala species in Central America. It differs quite sharply from other species of the group by the traits specified in the diagnosis, and its identification should not present any difficulties.

Lycogala australe

Leontyev, S.J. Lloyd & P. McDonald, sp. nov. MB 857847. Fig. 27.

Etymology: Australis (Latin) southern, referring to the occurrences of the species in Southern Hemisphere.

Diagnosis: Differs from other ‘crystalliferous’ species like L. leopardinum and L. succineum by the irregular elongated shape of peridial vesicles, which tend to merge to each other, and by small [2–3(–4) mm], solitary sporocarps.

Sporocarps solitary, spherical to short horizontally ovoid, regular in shape, (1.5–)2–3.5(–4.5) mm diam. Peridium membranous, light orange brown, covered by vesicles. Peridial vesicles (60–)120−160(–240) µm, in RL look like dried droplets, orange-brown, brown, semitranslucent, solitary or forming loose groups, convex or folded, more-or-less evenly distributed, distant from each other on 1–2 of their diam., in TL simple or forming loose aggregates, ovoid to elongate, light brown. Vesicle walls light brownish, thin (1–2 µm), 1–2-layered with outer layer somewhat granular. Crystals numerous, in form of scattered inclusions. Oil present in form of occasional yellow droplets and abundant, brownish, granular accumulations. Inner surface of the peridium smooth or covered by warts. Capillitium tubular, 2−10 µm diam., with wavy contour, surface fine pitted, with occasional ring-shaped islets. Spore mass light pinkish beige. Spores (6–)6.5–8 µm diam., hyaline, reticulate, 6–8 meshes across diam., unornamented area occupies 1/2–1/3 of the spore surface. Immature fructifications unknown.

Typus: Australia, Tasmania, Mount Roland area, 2 km W of Sheffield (-41.3717 146.2841), on the bark of fallen stringy bark tree, 27 Oct. 2022, P. McDonald (holotype MEL PMcD230). GenBank: nucSSU = PQ633834 (rg71); mtSSU = PQ633575.

Distribution: Australia (Tasmania), South America (Argentina).

Notes: Lycogala australe is well distinguished from other members of the ‘crystalliferous’ group by the traits outlined in the diagnosis. However, there is a possibility of confusing it with the ‘oily’ species like L. densum and L. guttatum, especially since the former is found in Australia. However, both similar species have very abundant oil accumulations and lack crystals.

Lycogala miserum

Leontyev & Schnittler, sp. nov. MB 857848. Fig. 28.

Etymology: Miser (Latin) wretched, miserable, referring to the poor development of sporocarps and indistinct diagnostic features.

Diagnosis: Differs from other ‘crystalliferous’ species like L. palianytsia by small irregular peridial vesicles filled with yellow oil accumulations, and by small (3−3.5 mm), solitary sporocarps.

Sporocarps solitary, spherical to short horizontally ovoid, regular in shape, (2.5–)3–3.5(–4) mm diam. Peridium membranous, light orange brown, covered by vesicles. Peridial vesicles (60–)100−150(–200) µm, in RL brown, solitary, folded, unevenly distributed, distant from each other on 2–4 of their diam., in TL simple, ovoid or angular, yellowish. Vesicle walls hyaline, thin (1 µm), single-layered. Crystals numerous, in form of scattered inclusions. Oil present in form of granular accumulations, brownish. Inner surface of the peridium smooth or covered by warts and rings. Capillitium tubular, 5–15 µm diam., with wavy contour, surface fine pitted, with occasional ring-shaped islets or more prominent rings. Spore mass warm grey. Spores (6–)6.5–8 µm diam., hyaline, reticulate, 5–7 meshes across diam., unornamented area indistinct, occupies 1/3–1/4 of the spore surface. Immature fructifications unknown.

Typus: Germany, Bavaria, Garmisch-Partenkirchen, northern Ammergauer Alps, near Brünstle Dienst-Hütte, gorge Sulzgraben (47.5195 11.0368), on dead wood, see Schnittler & Novozhilov (1998) for the detailed locality description, 1 Oct. 1997, M. Schnittler (holotype GFW sc20167). GenBank: nucSSU = OM423961 (rg20).

Distribution: Europe (Germany, Ukraine).

Notes: This is one of the most challenging species to identify. It closely resembles L. succineum and L. palianytsia, but these species are not prone to forming solitary sporocarps and are usually somewhat larger (up to 5 mm compared to the typical 3 mm for L. miserum). However, the oily accumulations, which are fairly abundant and have a yellowish hue, distinguish L. miserum among ‘crystalliferous’ species. Differentiating L. miserum from the ‘oily’ species, especially L. fuscoolearium and L. guttatum, is more complex. Nevertheless, these lack crystals and form groups of larger sporocarps.

Lycogala asperum

Leontyev, Ishchenko, T. van der Heul & Schnittler, sp. nov. MB 857849. Fig. 29.

Etymology: Asper (Latin) rough, harsh, uneven, referring to the uneven surface of peridium and capillitium.

Diagnosis: Differs from the rest of Lycogala species by the combination of small (2–3 mm) grouped sporocarps, dark, simple, convex, peridial vesicles, which accumulate big droplets of orange-yellow oil.

Sporocarps scattered, spherical to short horizontally ovoid, regular in shape, (1.5–)2–3(–3.5) mm diam. Peridium membranous, light yellowish brown, covered by vesicles. Peridial vesicles (80–)100–130(–170) µm, in RL dark brown, solitary or forming loose groups, folded, with convex central part, more-or-less evenly distributed, distant from each other on 1–3 of their diam., in TL simple, ovoid, elongate or irregular, light brownish. Vesicle walls light brownish, thin (1 µm), single-layered. Crystals absent. Oil droplets large (20–60 µm) and small, bright warm-yellow, very conspicuous on the translucent background. Inner surface of the peridium covered by numerous rings 1–2 µm diam. Capillitium tubular, 4–15 µm diam., with wavy contour, ornamented by folds and bracelet-like thickenings, with no pits. Spore mass light pinkish. Spores (5.5–)6.5–8 µm diam., hyaline, reticulate, 6–7 meshes across diam., unornamented area occupies 1/2–1/3 of the spore surface. Immature fructifications bright orange.

Typus: Russia, Primorsky Krai, Ussuriysky State Reserve, Komarovka valley, Grabovaya hill (43.63899 132.34963), оn the trunk of dead coniferous tree, 14 Aug. 2022, Y. Ishchenko (holotype GFW IY115). GenBank: nucSSU = PQ633768 (rg40); mtSSU = PQ633475; COI = PQ628493.

Distribution: Asia (Russia, Japan), Australia.

Notes: The new species shows some affinity to L. maculatum and L. irregulare, sharing with them the presence of simple peridial vesicles. However, its small size, the accumulation of orange-yellow oil, the bright orange pigmentation of immature sporocarps and the ring ornamentation of the peridium allow to distinguish L. asperum from these species. Other taxa with yellow oils either contain crystals (L. miserum) or are larger in size and have lighter vesicles (L. densum, L. guttatum).

DISCUSSION

Ribogroups and species

The genus Lycogala, which until 2023 included only five widely recognized species (Poulain et al. 2011), now comprises at least 43 species. This is undoubtedly not the final count, as at least 18 morphologically distinct species identified in our study remain undescribed. In addition, some of the already described taxa encompass multiple ribogroups. Further investigation, incorporating larger datasets, may allow for the separation of these aggregates into multiple biospecies.

Despite the broad geographic coverage of the collections used in our study, molecular data on Lycogala remain completely or almost entirely absent for Africa, South America, Central Asia, and other regions with rich and distinct biotas. Therefore, even our predicted count of 183 ribogroups (putative biospecies) within the genus is likely an underestimate of the actual genetic diversity of Lycogala.

In some cases, we decided to describe complexes of multiple ribogroups as single morphological species (L. densum, L. guttatum, L. squamatum) or, at least, to associate singleton ribogroups with closely related biospecies (L. pulchellum, L. rubrosporum, L. ustulatum). All these morphology-based entities also appear as monophyletic groups in our nucSSU phylogeny (Fig. S6) and in the three-gene phylogeny with the exception of L. squamatum (Fig. 3). However, grouping several related biospecies into a single morphospecies is a temporary measure driven by data limitations. Our experience shows that when numerous and/or well-preserved specimens are available, even very closely related Lycogala species can be distinguished morphologically (L. leopardinum and L. succineum, L. roseosporum and L. persicum, L. irregulare and L. epidendrum). Therefore, we expect that the nine genetically heterogeneous species currently recognized in our study (see Results) will eventually be subdivided into reproductively isolated biospecies.

However, the existence of cryptic Lycogala species, for which no unique combination of morphological traits can be found, cannot be ruled out. Such cases are known in myxomycetes. For instance, three cryptic species have been identified within Trichia varia (Feng & Schnittler 2015), with no clear morphological differences among them. Similarly, when describing Diacheopsis resinae, an aggregate of three reproductively isolated units, the authors preferred to define only a single morphological species due to the absence of distinct differences between biospecies (Gøtzsche et al. 2024). Eighteen reproductively isolated lineages have been discovered within Badhamia albescens, with at least some of them lacking pronounced morphological features (Shchepin et al. 2021). Obviously, closely related species do not necessarily exhibit phenotypic differences, as this requires either (1) selection pressure on visually identifiable traits or (2) a ‘fortunate’ course of genetic drift leading to the random accumulation of distinct morphological characteristics. Thus, phenotypic distinctiveness does not necessarily evolve in parallel with genetic, ecological, or physiological divergence. This often leads to discrepancies between morphologically and genetically recognizable species (De Queiroz 2007). Currently, within the myxomycete research community, the prevailing view is that our knowledge remains insufficient to formally describe species for which morphological differences from other taxa are (yet) unknown (Schnittler et al. 2025). To date, no truly cryptic species of myxomycetes have been formally described, and we refrain from doing so as well. Therefore, the decision to describe several related but isolated lineages under a shared species name may be practically justified even in the long term.

A separate case concerns L. exiguum. The type specimen of this species was examined by us (Leontyev & Schnittler 2023), allowing comparisons with modern collections. As a result, we identified a large complex comprising ten ribogroups (rg04, 24, 46, 50, 54, 58, 75, 80–82), whose representatives exhibit substantial similarity to L. exiguum, with rg54 and rg58 displaying the highest resemblance (Fig. 30). Unfortunately, the type material of L. exiguum was collected in 1894 and cannot be barcoded using traditional methods. At the current state of art, we consider the group of species morphologically similar to L. exiguum as a single species complex. However, one lineage within this complex (rg50), which exhibits distinct differences from the type material of L. exiguum, has been formally described as a new species, L. microcarpum (Fig. 19).

Variability of L. epidendrum s. str.

The species L. epidendrum s. str. has recently been redefined with a narrow circumscription, corresponding to ribogroup rg01 (Leontyev et al. 2023b). It was found that this species is the most widespread representative of the genus, at least in temperate regions of the Northern Hemisphere. In our 2023 dataset, L. epidendrum s. str. accounted for 44.3 % of the specimens; in the expanded collection analysed in this study, it constituted 35.6 % (the decrease may be due to the intentional selection of non-epidendrum specimens by at least some collectors). Unlike most species of Lycogala, L. epidendrum s. str. appears to have a cosmopolitan distribution, occurring in Eurasia, North America, and Australia (we do not have barcoding data from Africa, and the only specimen from South America belongs to a different species). This cosmopolitan distribution is accompanied by an extraordinary genetic polymorphism: within rg01, we identified 29 subgroups (Fig. S6), denoted here by alphanumeric indices. Some of these subgroups have more restricted distributions than the species as a whole – for example, rg01f is found only in Australia, while rg01l occurs in Asia and North America (Table S1). The remaining groups, represented by 10 or more specimens, are widely distributed across Eurasia.

The genetic diversity of L. epidendrum s. str. raises the question of its taxonomic unity. The distance-based species delimitation (the ASAP method) suggests that L. epidendrum s. str. may comprise between five (nucSSU) and 16 (mtSSU) distinct species (see Fig. 2). However, only two of the five nucSSU-based groups form external branches in the tree of L. epidendrum s. str. The topologies of the nucSSU and mtSSU trees differ significantly, both in terms of group composition and relationships among them.

Recombination test indicates that most subgroups of L. epidendrum s. str. display no between-group recombination. The exception is three clusters of subgroups (b1+b2+h+v+w, c+p, d+i), between which occasional recombination was observed (Fig. S4). Importantly, the clusters do not necessarily unite closely related subgroups (Fig. S6). These data suggest that at least some degree of mixing between subgroups may occur within L. epidendrum s. str. An alternative hypothesis is that shared alleles across different subgroups may have been inherited from a common ancestor (incomplete lineage sorting) or resulted from introgression at early stages of speciation (Wei et al. 2016, Zhou et al. 2017).

The lack of cross-mating between most of the L. epidendrum ribogroups cannot be sufficiently explained by geographic isolation, since several large, isolated groups (a, e, l, o, x) co-occur in Europe and other regions. However, barriers between ribogroups may be based on ecological factors such as seasonality or trophic preferences, rather than cellular incompatibility.

In summary, the species-level distinctiveness of at least some lineages within L. epidendrum s. str. is supported by the reproductive isolation test and ASAP partitioning. Conversely, arguments against recognizing these lineages as distinct species include the disagreement between species delimitation based on two genetic markers, the cases of hybridization between unrelated subgroups, and the partial inconsistency between ASAP-based delimitation and nucSSU tree topology.

Delimitation of sections

The taxonomic significance of morphological traits in Lycogala has been discussed in our previous studies (Leontyev et al. 2022, 2023b). We concluded that the structure of the peridium is a character of major taxonomic importance in Lycogala, and that there are several morphotypes of peridium. These morphotypes differ in the presence or absence of oil and crystals, in the pigmentation of the wall and content of the vesicles, and in their aggregation into complex structures. In the present study, we demonstrate that these variants correspond to the main phylogenetic lineages of the genus (Fig. 3), allowing us to formally describe them as sections.

The assignment of species to sections, supported by three-gene phylogeny and CST (see Figs 1, 2), is generally well-supported by their morphology. For example, species of section Crystallogala, although not necessarily characterized by a high concentration of crystals in vesicles, exhibit a distinctive habit that allows identification even without microscopic preparation. The aggregates of vesicles typical of section Tessellogala are also highly recognizable, as are the dark, glossy vesicles characteristic of Tinctogala. However, some species exhibit an intermediate morphology that would not have allowed their assignment to a specific section without phylogenetic data. For example, L. maculatum from sect. Lycogala is morphologically similar to species of Tinctogala. L. laeve, L. paraconfusum, and L. ustulatum from Tessellogala possess light-coloured, oil-accumulating vesicles, resembling those of section Oleogala. Some species with uncertain position within phylogenies (section incertae sedis) may be assigned to sections based on their morphology: L. pulchellum fits well to Tinctogala (and branches within this group in CST), L. oncoides and L. botrydium are similar to the members of Oleogala (although do not branch with this group in any phylogeny), L. asperum shares yellow oil and solitary vesicles with Crystallogala (but also does not branch with this section).

It remains uncertain whether the counterintuitive placement of some species within sections is the result of parallel evolution or merely an artefact of phylogenetic analysis. Further studies are needed to resolve this issue.

Difficulties of species identification

The species within sections are differentiated by a number of characteristics, often rather subtle, including fine colour variations, details of the spatial arrangement of peridial vesicles, and differences in sporocarp and spore sizes. Additionally, some species exhibit unique traits that enable reliable identification, such as the blue colouration of the spore mass in L. alisaulianovae or the distinctive spore ornamentation in L. olearium.

With the addition of 24 species described in this study, some traits previously considered species-specific have been found in multiple species. For example, the intense pink spore mass, initially thought to be unique to L. roseosporum, was also observed in L. persicum. Large oil droplets in single vesicles, originally reported only in L. olearium, were also found in L. densum, L. fuscoolearium, and L. oleocrystalliferum. Similarly, the orange pigmentation of mature vesicles under reflected light, previously described only in L. caviaroides, was also observed in certain specimens of L. olearium and L. oleocrystalliferum.

Among the newly described species, several exhibit unique traits previously unknown in Lycogala. These include olive-coloured sporocarps in L. olivaceum, red-orange spore mass in L. rubrosporum, and a spiny peridium in L. echinocarpum. Distinctive new patterns of vesicular aggregation were observed in L. microcarpum, L. rubrosporum, and L. squamatum. Another newly identified trait – the accumulation of bright yellow oil within vesicles – was found in multiple species, including L. asperum, L. guttatum, and L. miserum. Interestingly, yellow oil appears to be characteristic of species in the section Crystallogala that contain few or no crystals within their vesicles, which may serve as an auxiliary diagnostic criterion.

All species described by us in 2023, as well as almost all species newly described in this study, belong to the L. epidendrum complex and were originally labelled as such in all studied collections. Specimens with small sporocarps and dark vesicles were sometimes identified as L. exiguum, making the only exception to this rule. However, in this study, we describe one species that was previously associated with another complex, L. conicum. This species aggregate is currently represented by three ribogroups, one of which (rg65) corresponds to the classical description of the species (Lister 1925), while another (rg64) is described here as a separate species, L. sphaeroconicum. Notably, due to its intermediate morphology, this newly described species was also occasionally labelled as L. exiguum in some collections. The third species in this complex, L. ‘conicoides’ ad int., is represented by a single specimen from Australia and remains undescribed due to insufficient data.

Among the newly described species, as in the previous series of descriptions, some taxa are particularly challenging to identify. Major difficulties arise with morphologically similar species, such as L. skovorodaense – L. sigillatum, L. olearium – L. fuscoolerium – L. oleocrystalliferum, L. guttatum – L. melleum – L. succineum, and L. umbrinum – L. ustulatum. Further studies with a larger volume of field material may help determine the most reliable traits for distinguishing these species. However, it is important to emphasize that poor specimen condition, partial sclerotization or peridium damage, can make morphological identification impossible, especially in species with close morphological counterparts. A similar challenge arises with the fading of specimens preserved in herbaria for a long time (Leontyev et al. 2023b), which prevents the use of colour-based traits at both macroscopic and microscopic levels. In such cases, molecular barcoding remains the only reliable identification method. The importance of colour in a fresh state for identifying Lycogala once again underscores the value of this trait in myxomycetes (Yatsiuk et al. 2025) and highlights the need to document it when collecting specimens in the field or shortly thereafter (Schnittler et al. 2025).

To facilitate morphological species identification, we have developed a new identification key for the genus Lycogala (see below). The key excludes species that we consider dubious: L. fuscoviolaceum, L. leiosporum, and L. heterospora. It is based on qualitative macro- and micro-morphological traits that appear to be the most stable. Particular attention has been given to peridial structure, as it is species-specific in most cases. Quantitative traits are used only for distinguishing twin species.

Unexpectedly, Lycogala has proven to be a Klondike for taxonomists studying myxomycete species diversity. Research on this genus is only beginning and promises many future discoveries. Each of the species described in recent years must be further characterized in terms of its ecology, biology, distribution, and even biochemistry, as the diversity of colouration suggests potential interspecific differences in pigment composition. Everything previously known about the classical species Lycogala epidendrum sensu lato requires reassessment. A significant amount of work lies ahead, which can only be accomplished through consolidated efforts. We hope that our study will inspire colleagues to continue investigating one of the most well-known, and at the same time one of the least understood myxomycete.

Identification key to species of Lycogala

For recommendations on species identification, including the necessary tools and chemicals, see Leontyev et al. (2023b). Species described in this paper are marked in bold.

1a. Sporocarps taller than wide............................2
1b. Sporocarps isodiametric or broader than tall.........................3
2a. Sporocarps conical, wide spindle-like, with blunt or relatively acute end; vesicles inconspicuous, from a regular reticulum..........L. conicum
2b. Sporocarps egg-shaped, blunt spindle-shaped, to almost spherical; vesicles glossy, dark, do not from a regular reticulum.......................L. sphaeroconicum
3a. Sporocarps 2–5 cm diam., silvery grey, usually on soft-wooded living trees well above ground.............................L. flavofuscum
3b. Sporocarps < 2 cm diam., brown, greyish brown, ochraceous yellow, black, on dead wood, wooden debris or moss..............................4
4a. Spots on the peridium simple, consisting of one vesicle (visible under transmitted light)..........................................5
4b. Spots on the peridium compound, consisting of several to numerous tightly accreted vesicles forming aggregates (visible under transmitted light; in reflected light the spot may look pitted).....................................29
5a. Crystals inside vesicles absent or very scanty (check in PL). Vesicles of various types: rounded, spot-like, star-like, scattered or densely spaced at the peridium, coalescing to an irregular net...............................6
5b. Crystals inside vesicles numerous (visible in PL). Vesicles always rounded or short ovate, conspicuous, evenly distributed on the peridial surface, never forming a net...........................................22
6a. Vesicles dark brown to black in RL, brown in TL..................................7
6b. Vesicles light brownish in RL, almost hyaline in TL............................13
7a. Sporocarps pinkish, spore-mass bright pink...............................8
7b. Sporocarps not pinkish, spore mass of another colour...........................9
8a. Colonies small and compact; vesicles densely cover the upper part of the sporocarp; oily deposits inconspicuous, colourless......................................................................L. roseosporum
8b. Colonies vast and loose; vesicles more-or-less evenly distributed; oil droplets numerous, bright red.....................L. persicum
9a (7). Spore mass bluish grey, later greenish grey......................................L. alisaulianovae
9b. Spore mass beige, light grayish or pinkish........................................10
10a. Sporocarps solitary, small (≤ 2.5 mm) light yellow, densely covered with dark peridial vesicles, which give them a contrasting, spotty appearance.........................................................L. pulchellum (if vesicles are flat and glossy – check L. sphaeroconicum)
10b. Sporocarps in groups, medium-sized (2–5 mm diam.), in dark shades of brown; the contrast between vesicles and peridum less prominent........................................................................11
11a. Peridium background between vesicles dull ochraceous, dark grey brown, black............................L. maculatum
11b. Peridium background between vesicles reddish or lilac brown..................................12
12a. Peridium dark lilac-to umber-brown; vesicles angular, convex, forming loose groups, that merge into very fragmented reticulum; vesicle walls 2 µm thick.........................................................................L. umbrinum
12b. Peridium reddish brown; vesicles rounded, with a raised centre and a flat periphery, densely and evenly distributed; vesicle walls 5–20 µm thick; small aggregated thin-walled vesicles may be present around central simple thick-walled vesicle............L. ustulatum
13a (6). Oil deposits in vesicles scanty or absent.............................................14
13b. Oil droplets and granular oily matter abundant............................16
14a. Sporocarps somewhat olivaceous or greenish, or with faintest lemon yellow tint; the colour fades in old collections; spores 8.5–9.5 µm diam................................................L. olivaceum
14b. Sporocarps ochraceous- or greyish brown, with no green tint; spores 6.5–8.0 µm diam..............................15
15a. Sporocarps up to 15 mm diam., rounded, wide- to narrow-ovoid from mutual pressure. Peridium covered with fine whitish strands of dried slime, which may cover and hide vesicles and make the peridium to look uniformly smooth...........L. epidendrum
15b. Sporocarps up to 7 mm diam., rather irregular in shape even without mutual pressure. Strands of dried slime scanty, not hiding vesicles....................................L. irregulare (if capillitium is smooth, and vesicles tend to form rows – check L. laeve)
16a (13). Spores with 3–7 meshes across diam., with small meshes tending to surround every large mesh.................L. olearium
16b. Spores with 4–8 meshes across diam.; meshes are more-or-less similar in size....................................17
17a. Oil droplets colourless or dull yellowish or brownish; crystals may occur in vesicles....................................18
17b. Oil droplets bright yellow, orange yellow; crystals absent...............................21 (if the oil is red – check L. persicum; if vesicles contain crystals – check L. miserum)
18a. Vesicles distant from each other on 0.5–1 of their diam.; oil yellowish................................................19
18b. Vesicles distant from each other on 1–3 of their diam.; oil dull brownish..............................................20
19a. Sporocarps 3.5–6(–8) mm diam., light pinkish (?) when immature; vesicles 80–120 µm diam., very densely distributed..........L. densum
19b. Sporocarps 2.5–3(–4.5) mm diam., yellow when immature; vesicles 120–180 µm diam., not that densely distributed.............L. melleum
20a (18). Sporocarps 2.5–4(–6) mm diam.; vesicles 80–120 µm diam., brown........................L. fuscoolearium
20b. Sporocarps 4.5–7.5(–10) mm diam.; vesicles 110–150 µm diam., orange, orange-brown or brown.............L. oleocrystalliferum (if vesicles are orange or red, and filled with crystals – check L. caviaroides; if there are no crystals also check L. olearium, if there is no oil – check L. leopardinum)
21a (17). Sporocarps 4.0–5.5(–7.5) mm diam.; vesicles in RL light-brown, almost flat..............................L. guttatum
21b. Sporocarps 2.0–3.0(–3.5) mm diam.; vesicles in RL very dark brown, convex to conical..........................L. asperum
22a (5). Vesicles in RL orange red, dark red, looking like dried red caviar...............................L. caviaroides (if vesicle contains oil droplets and/or granular deposits – check L. olearium and L. oleocrystalliferum)
22b. Vesicles in RL amber yellow or brown..................................................23
23a. Sporocarps small (2–3 mm diam.), solitary; vesicles mostly merged into small blot-shaped groups; occurs in Southern Hemisphere................................................L. australe
23b. Sporocarps small or large, in groups; vesicle free, evenly distributed; occurs in Northern Hemisphere..........................24
24a. Vesicles mostly elongate, distant from each other by distances equaling 1–2 times their diam...........................25
24b. Vesicles mostly isodiametric, distances between them smaller than 1 times of their diam.................................26
25a. Sporocarps in groups, 2.5–5.5(–6.5) mm diam., vesicles do not contain oil........................L. palianytsia
25b. Sporocarps solitary, 3–3.5(–4) mm diam.; vesicles contain yellowish oil droplets.............................L. miserum
26a. Sporocarps 1.5–2.5(–3.5) mm diam., greyish; capillitium conspicuously verrucose; occurs in Neotropics............L. costaricanum
26b. Sporocarps 2–5(–10) mm diam., of various tints of brown; capillitium slightly verrucose to almost smooth..................27
27a. Vesicles amber yellow, light brown, distant from each other by 1 times of their diam..............................L. succineum (if immature sporocarps are yellow, and crystals almost absent – check L. melleum)
27b. Vesicles dark brown, distant from each other by 1/3–1/2 times of their diam.................................28
28a. Sporocarps up to 10 mm diam., occurs in Holarctic.....................................L. leopardinum
28b. Sporocarps up to 6 mm diam., occurs in Paleotropics.................................L. acinonychum
29a (4). Vesicle aggregates compact, with more-or-less smooth contour......................................30
29b. Vesicle aggregates loose, in form of branched rows, or aggregated vesicles covering entire surface of the peridium...........39
30a. Aggregates of vesicles large, typically with > 8 vesicles in one group.........................................31
30b. Aggregates of vesicles small, typically with < 8 vesicles in one group..............................................37
31a. Aggregates look like prominent papillate protrusions, longer than wide, giving the sporocarps an obvious spiny appearance..........................................L. echinocarpum
31b. Aggregates less convex; sporocarps smooth or somewhat verrucose............................................32
32a. Aggregates in RL look like black spots of rosette shape with bigger vesicles grouped at the centre.........................33
32b. Aggregates in RL do not have a rosette shape.........................................35
33a. Spore mass red, bright orangec red, occurs in Asia..................................L. rubrosporum
33b. Spore-mass beige; other distribution......................................................34
34a. Lines between rosette-shaped vesicle aggregates dark, regular; oil droplets in vesicles reddish; occurs in Holarctic..........L. squamatum
34b. Lines between rosette-shaped vesicle light, rather inconspicuous; oil droplets in vesicles colourless; occurs in Neotropics......................................................L. aggregatum
35a (32). Aggregates in RL mat, angular, with amorphous surface; vesicle walls hardly visible in TL..............................L. botrydium
35b. Aggregates in RL glossy, with smooth contour and clearly pitted surface; vesicle walls well visible in TL.............................36
36a. Aggregates ovoid in shape, sometimes fused but not forming a reticulum...........................L. microcarpum
36b. Aggregates blot-shaped, branched, forming a regular reticulum................................L. exiguum
37a (30). Vesicles filled with dark brown oil material and contain crystals (see in PL)...........................L. oncoides
37b. Vesicles filled with distinguishable colourless oil droplets and do not contain crystals................................38
38a. Peridium dull greyish, vesicles dull brown in RL; capillitium warty, sometimes spiny.............................L. skovorodaense
38b. Peridium light orange-brown, vesicles dark red brown in RL; capillitium looks smooth under LM.................L. sigillatum
39a (29). Sporocarps small (2–3 mm), solitary, loosely covered with branched rows of elongate vesicles...............L. inconspicuum
39b. Sporocarps larger (> 3 mm), grouped, densely covered by vesicles, which form a reticulum, irregular patches or spots..............40
40a. Peridium with clear, contrast vesicle pattern in RL..........................................41
40b. Peridium with blurred, indistinct vesicle pattern in RL.....................................................44
41a. Vesicles of two types, large solitary, with very thick brownish walls (5–20 µm), and small aggregated, thin-walled (1–2 µm), forming irregular network around large ones.......................................................L. ustulatum (see also paragraph 12)
41b. Vesicles only thin-walled, more-or-less uniform.....................................42
42a. Vesicles nearly black in RL, dark brown in TL, with the thick, brownish outer layer.................................L. nigroconfusum
42b. Vesicles brown in RL, light brownish in TL, with indistinct, colourless outer layer...................................43
43a. Sporocarps rather irregular in shape; vesicles 40–90 µm diam., forming a characteristic ‘marble’ pattern of large lighter and darker spots; oil droplets colourless; spores 5.5–8 μm...........................................L. confusum
43b. Sporocarps regular in shape; vesicles 30–60 µm diam., evenly distributed with no marble pattern; oil droplets often reddish; spores 7–9 µm........................................................L. paraconfusum
44s. Sporocarps dark brown to almost black; oil colourless; capillitium warty; spores 5.5–7.5 µm......................L. fossiculatum
44b. Sporocarps light greyish brown; oil brownish or reddish; capillitium smooth; spores 6.5–8.5 µm.....................L. laeve

ACKNOWLEDGEMENTS

We first and foremost want to thank numerous ardent collectors: without their continued support and engagement a study like this would not have been possible. DL wishes to acknowledge the Humbold foundation (fellowship 2019–2023), and the DAAD program (fellowship 2024). Special gratitude is expressed to Dr. Rabea Schlüter (University of Greifswald) for the assistance during the SEM study. Molecular investigations were in part supported by grants of the DFG (RTG 2010 and SCHN1080/6-1) to MS.

Conflict of interest:

The authors declare no conflicts of interest.

Supplementary Material: http://fuse-journal.org/

Fig. S1

Preliminary species delimitation based on ASAP analysis of the nucSSU alignment. The five best score partitions are shown.

fuse-2025-16-7-FigS1.pdf^{(877.1KB, pdf)}

Fig. S2

Preliminary species delimitation based on ASAP analysis of the mtSSU alignment. The five best score partitions are shown.

fuse-2025-16-7-FigS2.pdf^{(503.8KB, pdf)}

Fig. S3

Preliminary species delimitation based on ASAP analysis of the COI alignment. The five best score partitions are shown.

fuse-2025-16-7-FigS3.pdf^{(253.9KB, pdf)}

Fig. S4

Recombination test by LineChart for ribogroups of Lycogala spp. Ribogroups belonging to L. epidendrum are shown in red.

fuse-2025-16-7-FigS4.pdf^{(1.1MB, pdf)}

Fig. S5

Recombination test by LineChart for morphospecies of Lycogala spp.

fuse-2025-16-7-FigS5.pdf^{(875.5KB, pdf)}

Fig. S6

Maximum likelihood phylogeny of 706 nucSSU sequences of Lycogala spp. Branch support is shown as follows: Shimodara-Hasegawa SH-aLRT test / Approximate Bayes test / Ultrafast bootstrap (1000 true replicates). Colours indicate assignment of species to sections.

fuse-2025-16-7-FigS6.pdf^{(44.6KB, pdf)}

Fig. S7

Maximum likelihood phylogeny of 273 mtSSU sequences of Lycogala spp. Branch support is shown as follows: Shimodara-Hasegawa SH-aLRT test / Approximate Bayes test / Ultrafast bootstrap (1000 true replicates). Colours indicate assignment of species to sections.

fuse-2025-16-7-FigS7.pdf^{(15.5KB, pdf)}

Fig. S8

Maximum likelihood phylogeny of 130 COI sequences of Lycogala spp. Branch support is shown as follows: Shimodara-Hasegawa SH-aLRT test / Approximate Bayes test / Ultrafast bootstrap (1000 true replicates). Colours indicate assignment of species to sections.

fuse-2025-16-7-FigS8.pdf^{(8.4KB, pdf)}

Fig. S9

Three-gene Bayesian phylogeny based on concatenated three-gene dataset of 191 representative specimens of Lycogala, trimmed in GBlocks as described in Methods.

fuse-2025-16-7-FigS9.pdf^{(13.3KB, pdf)}

File S1

MAFFT alignment of partial nucSSU sequences of 706 specimens of Lycogala spp. (fasta file).

fuse-2025-16-7-FileS1.fasta^{(1.1MB, fasta)}

File S2

MAFFT alignment of partial mtSSU sequences of 273 specimens of Lycogala spp. (fasta file).

fuse-2025-16-7-FileS2.fasta^{(134.2KB, fasta)}

File S3

MAFFT alignment of partial COI sequences of 130 specimens of Lycogala spp. (fasta file).

fuse-2025-16-7-FileS3.fasta^{(84.2KB, fasta)}

Table S1

Collection and barcoding data for all studied specimens of Lycogala.

fuse-2025-16-7-TableS1.xlsx^{(134KB, xlsx)}

Table S2

Measurements of sporocarps, peridial vesicles, capillitium and spores (in separate sheets) for the species of Lycogala described in this study.

fuse-2025-16-7-TableS2.xlsx^{(94.1KB, xlsx)}

REFERENCES

Castresana J. (2000). Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis. Molecular Biology and Evolution 17: 540–552. 10.1093/oxfordjournals.molbev.a026334 [DOI] [PubMed] [Google Scholar]
De Queiroz K. (2007). Species concepts and species delimitation. Systematic Biology 56: 879–886. 10.1080/10635150701701083 [DOI] [PubMed] [Google Scholar]
Feng Y, Schnittler M. (2015). Sex or no sex? Group I introns and independent marker genes reveal the existence of three sexual but reproductively isolated biospecies in Trichia varia (Myxomycetes). Organisms Diversity & Evolution 15: 631–650. 10.1007/s13127-015-0230-x [DOI] [Google Scholar]
García-Cunchillos I, Zamora JC, Ryberg M, et al. (2022). Phylogeny and evolution of morphological structures in a highly diverse lineage of fruiting-body-forming amoebae, order Trichiales (Myxomycetes, Amoebozoa). Molecular Phylogenetics and Evolution 177: 107609. 10.1016/j.ympev.2022.107609 [DOI] [PubMed] [Google Scholar]
Gøtzsche HF, Woerly B, Popa F, et al. (2024). A new species of Diacheopsis (Myxomycetes) and a new habitat for myxomycetes. Mycologia: 1–18. 10.1080/00275514.2024.2413343 [DOI] [PubMed] [Google Scholar]
Hall TA. (1999). BioEdit: A user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98. [Google Scholar]
Johannesen EW, Vetlesen P. (2024). New and rare myxomycetes (Mycetozoa, Myxogastria) in Norway Part 2. Agarica 44: 25–84. 10.5617/agarica.11615 [DOI] [Google Scholar]
Jones EP, Mahendran R, Spottswood MR, et al. (1990). Mitochondrial DNA of Physarum polycephalum: Physical mapping, cloning and transcription mapping. Current Genetics 17: 331–337. 10.1007/BF00314881 [DOI] [PubMed] [Google Scholar]
Kalyaanamoorthy S, Minh BQ, Wong TKF, et al. (2017). ModelFinder: Fast model selection for accurate phylogenetic estimates. Nature Methods 14: 587–589. 10.1038/nmeth.4285 [DOI] [PMC free article] [PubMed] [Google Scholar]
Katoh K, Rozewicki J, Yamada KD. (2019). MAFFT online service: Multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics 20: 1160–1166. 10.1093/bib/bbx108 [DOI] [PMC free article] [PubMed] [Google Scholar]
Lado C. (2005–2025). An on-line nomenclatural information system of Eumycetozoa. http://www.eumycetozoa.com [accessed 13 Mar 2025]
Leontyev D, Buttgereit M, Kochergina A, et al. (2023a). Two independent genetic markers support separation of the myxomycete Lycogala epidendrum into numerous biological species. Mycologia 115: 32–43. 10.1080/00275514.2022.2133526 [DOI] [PubMed] [Google Scholar]
Leontyev D, Ishchenko Y, Schnittler M. (2023b). Fifteen new species from the myxomycete genus Lycogala. Mycologia 115: 524–560. 10.1080/00275514.2023.2199109 [DOI] [PubMed] [Google Scholar]
Leontyev D, Moroz E, Schnittler M. (2024). Molecular barcoding of herbarium collections reveals diversity of Reticulariaceae (Myxomycetes) in Belarus. Nova Hedwigia 119: 369–386. 10.1127/nova_hedwigia/2024/1029 [DOI] [Google Scholar]
Leontyev D, Schnittler M. (2017). The phylogeny of myxomycetes. In: Myxomycetes: Biology, Systematics, Biogeography and Ecology (Stephenson SL, Rojas C, eds). Press, Country: 83–106. 10.1016/B978-0-12-805089-7.00003-2 [DOI] [Google Scholar]
Leontyev D, Schnittler M. (2022). The phylogeny and phylogenetically based classification of myxomycetes. In: Myxomycetes (Stephenson SL, Rojas C, eds). Elsevier: 97–124. 10.1016/B978-0-12-824281-0.00008-7 [DOI] [Google Scholar]
Leontyev D, Schnittler M. (2023). What are Lycogala confusum and L. exiguum? Revising authentic collections of myxomycetes in the light of a molecular-aided species concept. Nova Hedwigia 116: 403–416. 10.1127/nova_hedwigia/2023/0820 [DOI] [Google Scholar]
Leontyev D, Schnittler M, Ishchenko Y, et al. (2022). Another species complex in myxomycetes: Diversity of peridial structures in Lycogala epidendrum. Nova Hedwigia 114: 413–434. 10.1127/nova_hedwigia/2022/0690 [DOI] [Google Scholar]
McHugh R, Reid C. (2008). Aethalium cortex formation in the myxomycete Lycogala terrestre. Revista Mexicana de Micología 27: 53–57. [Google Scholar]
Poulain M, Meyer M, Bozonnet J. (2011). Les Myxomycètes. 1. Guide de Détermination. Fédération mycologique et botanique Dauphiné-Savoie, Sevrier. [Google Scholar]
Puillandre N, Brouillet S, Achaz G. (2021). ASAP: Assemble species by automatic partitioning. Molecular Ecology Resources 21: Article 2. 10.1111/1755-0998.13281 [DOI] [PubMed] [Google Scholar]
Rambaut A. (2018). FigTree. Version 1.4.4. Institute of Evolutionary Biology, University of Edinburgh, Edinburgh. [Google Scholar]
Rambaut A, Drummond AJ, Xie D, et al. (2018). Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. Systematic Biology 67: 901–904. 10.1093/sysbio/syy032 [DOI] [PMC free article] [PubMed] [Google Scholar]
Rannala B, Yang Z. (2003). Bayes estimation of species divergence times and ancestral population sizes using DNA sequences from multiple loci. Genetics 164: 1645–1656. 10.1093/genetics/164.4.1645 [DOI] [PMC free article] [PubMed] [Google Scholar]
Riedel A, Sagata K, Suhardjono YR, et al. (2013). Integrative taxonomy on the fast track—Towards more sustainability in biodiversity research. Frontiers in Zoology 10: 15. 10.1186/1742-9994-10-15 [DOI] [PMC free article] [PubMed] [Google Scholar]
Ronquist F, Teslenko M, van der Mark P, et al. (2012). MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542. 10.1093/sysbio/sys029 [DOI] [PMC free article] [PubMed] [Google Scholar]
Sayyari E, Mirarab S. (2016). Fast coalescent-based computation of local branch support from quartet frequencies. Molecular Biology and Evolution 33: 1654–1668. 10.1093/molbev/msw079 [DOI] [PMC free article] [PubMed] [Google Scholar]
Schnittler M, Leontyev D, Yatsiuk I, et al. (2025). Species descriptions in myxomycetes – can we settle on rules for good taxonomic practice? IMA Fungus 16: e141199. 10.3897/imafungus.16.141199 [DOI] [PMC free article] [PubMed] [Google Scholar]
Schnittler M, Novozhilov YK. (1998). Late-autumn myxomycetes of the Northern Ammergauer Alps. Nova Hedwigia 66: 205–222. 10.1127/nova.hedwigia/66/1998/205 [DOI] [Google Scholar]
Shchepin O, Novozhilov Y, Woyzichovski J, et al. (2021). Genetic structure of the protist Physarum albescens (Amoebozoa) revealed by multiple markers and genotyping by sequencing. Molecular Ecology 31: 372–390. 10.1111/mec.16239 [DOI] [PubMed] [Google Scholar]
Song WL, Yan SZ, Chen SL. (2024). Morphological and phylogenetic analyses reveal four species of myxomycetes new to China. Archives of Microbiology 206: 364. 10.1007/s00203-024-04083-4 [DOI] [PubMed] [Google Scholar]
Tamura K, Stecher G, Kumar S. (2021). MEGA11: Molecular evolutionary genetics analysis version 11. Molecular Biology and Evolution 38: 3022–3027. 10.1093/molbev/msab120 [DOI] [PMC free article] [PubMed] [Google Scholar]
Trifinopoulos J, Nguyen L-T, von Haeseler A, et al. (2016). W-IQ-TREE: A fast online phylogenetic tool for maximum likelihood analysis. Nucleic Acids Research 44: W232–W235. 10.1093/nar/gkw256 [DOI] [PMC free article] [PubMed] [Google Scholar]
Wei X, McCune B, Lumbsch HT, et al. (2016). Limitations of species delimitation based on phylogenetic analyses: A case study in the Hypogymnia hypotrypa group (Parmeliaceae, Ascomycota). PLoS ONE 11: e0163664. 10.1371/journal.pone.0163664 [DOI] [PMC free article] [PubMed] [Google Scholar]
Yatsiuk I, Leontyev D, Schnittler M, et al. (2025). Arcyria and allied genera: taxonomic backbone and character evolution. Fungal Systematics and Evolution 15: 97–118. 10.3114/fuse.2025.15.04 [DOI] [PMC free article] [PubMed] [Google Scholar]
Yatsiuk I, Leshchenko Y, Viunnyk V, et al. (2024). The comprehensive checklist of myxomycetes of Ukraine, based on extended occurrence and reference datasets. Biodiversity Data Journal 12: e120891. 10.3897/BDJ.12.e120891 [DOI] [PMC free article] [PubMed] [Google Scholar]
Zhang C, Mirarab S. (2022). Weighting by gene tree uncertainty improves accuracy of quartet-based species trees. Molecular Biology and Evolution 39: msac215. 10.1093/molbev/msac215 [DOI] [PMC free article] [PubMed] [Google Scholar]
Zhou Y, Duvaux L, Ren G, et al. (2017). Importance of incomplete lineage sorting and introgression in the origin of shared genetic variation between two closely related pines with overlapping distributions. Heredity 118: 211–220. 10.1038/hdy.2016.72 [DOI] [PMC free article] [PubMed] [Google Scholar]

Associated Data

This section collects any data citations, data availability statements, or supplementary materials included in this article.

Supplementary Materials

Fig. S1

Preliminary species delimitation based on ASAP analysis of the nucSSU alignment. The five best score partitions are shown.

fuse-2025-16-7-FigS1.pdf^{(877.1KB, pdf)}

Fig. S2

Preliminary species delimitation based on ASAP analysis of the mtSSU alignment. The five best score partitions are shown.

fuse-2025-16-7-FigS2.pdf^{(503.8KB, pdf)}

Fig. S3

Preliminary species delimitation based on ASAP analysis of the COI alignment. The five best score partitions are shown.

fuse-2025-16-7-FigS3.pdf^{(253.9KB, pdf)}

Fig. S4

Recombination test by LineChart for ribogroups of Lycogala spp. Ribogroups belonging to L. epidendrum are shown in red.

fuse-2025-16-7-FigS4.pdf^{(1.1MB, pdf)}

Fig. S5

Recombination test by LineChart for morphospecies of Lycogala spp.

fuse-2025-16-7-FigS5.pdf^{(875.5KB, pdf)}

Fig. S6

fuse-2025-16-7-FigS6.pdf^{(44.6KB, pdf)}

Fig. S7

fuse-2025-16-7-FigS7.pdf^{(15.5KB, pdf)}

Fig. S8

fuse-2025-16-7-FigS8.pdf^{(8.4KB, pdf)}

Fig. S9

Three-gene Bayesian phylogeny based on concatenated three-gene dataset of 191 representative specimens of Lycogala, trimmed in GBlocks as described in Methods.

fuse-2025-16-7-FigS9.pdf^{(13.3KB, pdf)}

File S1

MAFFT alignment of partial nucSSU sequences of 706 specimens of Lycogala spp. (fasta file).

fuse-2025-16-7-FileS1.fasta^{(1.1MB, fasta)}

File S2

MAFFT alignment of partial mtSSU sequences of 273 specimens of Lycogala spp. (fasta file).

fuse-2025-16-7-FileS2.fasta^{(134.2KB, fasta)}

File S3

MAFFT alignment of partial COI sequences of 130 specimens of Lycogala spp. (fasta file).

fuse-2025-16-7-FileS3.fasta^{(84.2KB, fasta)}

Table S1

Collection and barcoding data for all studied specimens of Lycogala.

fuse-2025-16-7-TableS1.xlsx^{(134KB, xlsx)}

Table S2

Measurements of sporocarps, peridial vesicles, capillitium and spores (in separate sheets) for the species of Lycogala described in this study.

fuse-2025-16-7-TableS2.xlsx^{(94.1KB, xlsx)}

[R1] Castresana J. (2000). Selection of conserved blocks from multiple alignments for their use in phylogenetic analysis. Molecular Biology and Evolution 17: 540–552. 10.1093/oxfordjournals.molbev.a026334 [DOI] [PubMed] [Google Scholar]

[R2] De Queiroz K. (2007). Species concepts and species delimitation. Systematic Biology 56: 879–886. 10.1080/10635150701701083 [DOI] [PubMed] [Google Scholar]

[R3] Feng Y, Schnittler M. (2015). Sex or no sex? Group I introns and independent marker genes reveal the existence of three sexual but reproductively isolated biospecies in Trichia varia (Myxomycetes). Organisms Diversity & Evolution 15: 631–650. 10.1007/s13127-015-0230-x [DOI] [Google Scholar]

[R4] García-Cunchillos I, Zamora JC, Ryberg M, et al. (2022). Phylogeny and evolution of morphological structures in a highly diverse lineage of fruiting-body-forming amoebae, order Trichiales (Myxomycetes, Amoebozoa). Molecular Phylogenetics and Evolution 177: 107609. 10.1016/j.ympev.2022.107609 [DOI] [PubMed] [Google Scholar]

[R5] Gøtzsche HF, Woerly B, Popa F, et al. (2024). A new species of Diacheopsis (Myxomycetes) and a new habitat for myxomycetes. Mycologia: 1–18. 10.1080/00275514.2024.2413343 [DOI] [PubMed] [Google Scholar]

[R6] Hall TA. (1999). BioEdit: A user-friendly biological sequence alignment editor and analysis program for Windows 95/98/NT. Nucleic Acids Symposium Series 41: 95–98. [Google Scholar]

[R7] Johannesen EW, Vetlesen P. (2024). New and rare myxomycetes (Mycetozoa, Myxogastria) in Norway Part 2. Agarica 44: 25–84. 10.5617/agarica.11615 [DOI] [Google Scholar]

[R8] Jones EP, Mahendran R, Spottswood MR, et al. (1990). Mitochondrial DNA of Physarum polycephalum: Physical mapping, cloning and transcription mapping. Current Genetics 17: 331–337. 10.1007/BF00314881 [DOI] [PubMed] [Google Scholar]

[R9] Kalyaanamoorthy S, Minh BQ, Wong TKF, et al. (2017). ModelFinder: Fast model selection for accurate phylogenetic estimates. Nature Methods 14: 587–589. 10.1038/nmeth.4285 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R10] Katoh K, Rozewicki J, Yamada KD. (2019). MAFFT online service: Multiple sequence alignment, interactive sequence choice and visualization. Briefings in Bioinformatics 20: 1160–1166. 10.1093/bib/bbx108 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R11] Lado C. (2005–2025). An on-line nomenclatural information system of Eumycetozoa. http://www.eumycetozoa.com [accessed 13 Mar 2025]

[R12] Leontyev D, Buttgereit M, Kochergina A, et al. (2023a). Two independent genetic markers support separation of the myxomycete Lycogala epidendrum into numerous biological species. Mycologia 115: 32–43. 10.1080/00275514.2022.2133526 [DOI] [PubMed] [Google Scholar]

[R13] Leontyev D, Ishchenko Y, Schnittler M. (2023b). Fifteen new species from the myxomycete genus Lycogala. Mycologia 115: 524–560. 10.1080/00275514.2023.2199109 [DOI] [PubMed] [Google Scholar]

[R14] Leontyev D, Moroz E, Schnittler M. (2024). Molecular barcoding of herbarium collections reveals diversity of Reticulariaceae (Myxomycetes) in Belarus. Nova Hedwigia 119: 369–386. 10.1127/nova_hedwigia/2024/1029 [DOI] [Google Scholar]

[R15] Leontyev D, Schnittler M. (2017). The phylogeny of myxomycetes. In: Myxomycetes: Biology, Systematics, Biogeography and Ecology (Stephenson SL, Rojas C, eds). Press, Country: 83–106. 10.1016/B978-0-12-805089-7.00003-2 [DOI] [Google Scholar]

[R16] Leontyev D, Schnittler M. (2022). The phylogeny and phylogenetically based classification of myxomycetes. In: Myxomycetes (Stephenson SL, Rojas C, eds). Elsevier: 97–124. 10.1016/B978-0-12-824281-0.00008-7 [DOI] [Google Scholar]

[R17] Leontyev D, Schnittler M. (2023). What are Lycogala confusum and L. exiguum? Revising authentic collections of myxomycetes in the light of a molecular-aided species concept. Nova Hedwigia 116: 403–416. 10.1127/nova_hedwigia/2023/0820 [DOI] [Google Scholar]

[R18] Leontyev D, Schnittler M, Ishchenko Y, et al. (2022). Another species complex in myxomycetes: Diversity of peridial structures in Lycogala epidendrum. Nova Hedwigia 114: 413–434. 10.1127/nova_hedwigia/2022/0690 [DOI] [Google Scholar]

[R19] McHugh R, Reid C. (2008). Aethalium cortex formation in the myxomycete Lycogala terrestre. Revista Mexicana de Micología 27: 53–57. [Google Scholar]

[R20] Poulain M, Meyer M, Bozonnet J. (2011). Les Myxomycètes. 1. Guide de Détermination. Fédération mycologique et botanique Dauphiné-Savoie, Sevrier. [Google Scholar]

[R21] Puillandre N, Brouillet S, Achaz G. (2021). ASAP: Assemble species by automatic partitioning. Molecular Ecology Resources 21: Article 2. 10.1111/1755-0998.13281 [DOI] [PubMed] [Google Scholar]

[R22] Rambaut A. (2018). FigTree. Version 1.4.4. Institute of Evolutionary Biology, University of Edinburgh, Edinburgh. [Google Scholar]

[R23] Rambaut A, Drummond AJ, Xie D, et al. (2018). Posterior summarisation in Bayesian phylogenetics using Tracer 1.7. Systematic Biology 67: 901–904. 10.1093/sysbio/syy032 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R24] Rannala B, Yang Z. (2003). Bayes estimation of species divergence times and ancestral population sizes using DNA sequences from multiple loci. Genetics 164: 1645–1656. 10.1093/genetics/164.4.1645 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R25] Riedel A, Sagata K, Suhardjono YR, et al. (2013). Integrative taxonomy on the fast track—Towards more sustainability in biodiversity research. Frontiers in Zoology 10: 15. 10.1186/1742-9994-10-15 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R26] Ronquist F, Teslenko M, van der Mark P, et al. (2012). MrBayes 3.2: Efficient Bayesian phylogenetic inference and model choice across a large model space. Systematic Biology 61: 539–542. 10.1093/sysbio/sys029 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R27] Sayyari E, Mirarab S. (2016). Fast coalescent-based computation of local branch support from quartet frequencies. Molecular Biology and Evolution 33: 1654–1668. 10.1093/molbev/msw079 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R28] Schnittler M, Leontyev D, Yatsiuk I, et al. (2025). Species descriptions in myxomycetes – can we settle on rules for good taxonomic practice? IMA Fungus 16: e141199. 10.3897/imafungus.16.141199 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R29] Schnittler M, Novozhilov YK. (1998). Late-autumn myxomycetes of the Northern Ammergauer Alps. Nova Hedwigia 66: 205–222. 10.1127/nova.hedwigia/66/1998/205 [DOI] [Google Scholar]

[R30] Shchepin O, Novozhilov Y, Woyzichovski J, et al. (2021). Genetic structure of the protist Physarum albescens (Amoebozoa) revealed by multiple markers and genotyping by sequencing. Molecular Ecology 31: 372–390. 10.1111/mec.16239 [DOI] [PubMed] [Google Scholar]

[R31] Song WL, Yan SZ, Chen SL. (2024). Morphological and phylogenetic analyses reveal four species of myxomycetes new to China. Archives of Microbiology 206: 364. 10.1007/s00203-024-04083-4 [DOI] [PubMed] [Google Scholar]

[R32] Tamura K, Stecher G, Kumar S. (2021). MEGA11: Molecular evolutionary genetics analysis version 11. Molecular Biology and Evolution 38: 3022–3027. 10.1093/molbev/msab120 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R33] Trifinopoulos J, Nguyen L-T, von Haeseler A, et al. (2016). W-IQ-TREE: A fast online phylogenetic tool for maximum likelihood analysis. Nucleic Acids Research 44: W232–W235. 10.1093/nar/gkw256 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R34] Wei X, McCune B, Lumbsch HT, et al. (2016). Limitations of species delimitation based on phylogenetic analyses: A case study in the Hypogymnia hypotrypa group (Parmeliaceae, Ascomycota). PLoS ONE 11: e0163664. 10.1371/journal.pone.0163664 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R35] Yatsiuk I, Leontyev D, Schnittler M, et al. (2025). Arcyria and allied genera: taxonomic backbone and character evolution. Fungal Systematics and Evolution 15: 97–118. 10.3114/fuse.2025.15.04 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R36] Yatsiuk I, Leshchenko Y, Viunnyk V, et al. (2024). The comprehensive checklist of myxomycetes of Ukraine, based on extended occurrence and reference datasets. Biodiversity Data Journal 12: e120891. 10.3897/BDJ.12.e120891 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R37] Zhang C, Mirarab S. (2022). Weighting by gene tree uncertainty improves accuracy of quartet-based species trees. Molecular Biology and Evolution 39: msac215. 10.1093/molbev/msac215 [DOI] [PMC free article] [PubMed] [Google Scholar]

[R38] Zhou Y, Duvaux L, Ren G, et al. (2017). Importance of incomplete lineage sorting and introgression in the origin of shared genetic variation between two closely related pines with overlapping distributions. Heredity 118: 211–220. 10.1038/hdy.2016.72 [DOI] [PMC free article] [PubMed] [Google Scholar]

PERMALINK

Expanding Lycogala: twenty-four new species, their morphology and phylogenetic relationships

D Leontyev

Y Ishchenko

M Leontieva

I Yatsiuk

O Shchepin

W-L Song

SL Chen

E Moroz

M Schnittler

Abstract

INTRODUCTION

MATERIALS AND METHODS

Collections

Fig. 1.

Morphological study

DNA studies

Phylogenetic analysis

Species delimitation

RESULTS

Molecular delimitation of species

Fig. 2.

Morphological delimitation of species

Fig. 5.

Fig. 7.

Fig. 9.

Fig. 29.

Deep phylogeny and delimitation of sections

Fig. 3.

Fig. 4.

TAXONOMY

Lycogala sect. Lycogala

Lycogala sect.

Lycogala sect.

Lycogala sect.

Lycogala sect.

Lycogala sect.

Lycogala persicum

Lycogala pulchellum

Fig. 6.

Lycogala sphaeroconicum

Fig. 8.

Lycogala umbrinum

Lycogala ustulatum

Fig. 10.

Lycogala olivaceum

Fig. 11.

Lycogala laeve

Fig. 12.

Lycogala paraconfusum

Fig. 13.

Lycogala nigroconfusum

Fig. 14.

Lycogala inconspicuum

Fig. 15.

Lycogala echinocarpum

Fig. 16.

Lycogala rubrosporum

Fig. 17.

Lycogala squamatum

Fig. 18.

Lycogala microcarpum

Fig. 19.

Fig. 30.

Lycogala sigillatum

Fig. 20.

Lycogala fuscoolearium

Fig. 21.

Lycogala densum

Fig. 22.

Lycogala oleocrystalliferum

Fig. 23.

Lycogala guttatum

Fig. 24.

Lycogala melleum

Fig. 25.

Lycogala costaricanum

Fig. 26.

Lycogala australe