Four new species of Mycenasect.Calodontes (Agaricales, Mycenaceae) from northeast China

Abstract

Species of Mycenasect.Calodontes are representative of the Mycena genus as a whole and are easily recognised by the pinkish, reddish, purplish to brownish pileus and larger basidiomata. Furthermore, the colour of the pileus in the species of sect. Calodontes often has a transition or changes in different stages and the combination of the colour of the pileus with cystidia and basidiospores can be used to recognise taxa within this section. To date, 19 species of Mycenasect.Calodontes have been reported worldwide. Including our recent description of M.yuezhuoi, five species of sect. Calodontes have been recorded in China. During examination of specimens collected in coniferous forests or mixed broadleaf-conifer forests in temperate regions of China, additional taxa assigned to sect. Calodontes were identified. Four new species are recognised, based mostly on characters of the pileus and cystidia. Phylogenetic analysis of sequence data from multiple DNA regions (ITS + rpb1 + tef1) supported the morphological evidence. Here, we propose M.polycystidiata, M.rufobrunnea, M.shengshanensis and M.subulata as new species in Mycenasect.Calodontes. Morphological descriptions, line drawings, habitat photos and comparisons with closely-related taxa are provided. A key to the 23 known species of sect. Calodontes is presented.

Introduction

Mycenasect.Calodontes (Fr. ex Berk.) Quél. comprises the taxa in Mycena (Pers.) Roussel with a pinkish, reddish, purplish to brownish and mostly hygrophanous pileus, interveined lamellae, smooth cheilocystidia and pleurocystidia (if present) and mostly amyloid spores (Fries 1821; Berkeley 1836; Maas Geesteranus 1992a, 1992b; Harder et al. 2010). The group was initially proposed as Agaricustrib.Clitocybe subtrib. Calodontes Fries consisting of six species, then elevated to section rank within Agaricussubgen.Clitocybe Fr. ex Berk. and finally assigned to Mycena in 1872 (Fries 1821; Berkeley 1836; Quélet 1872). To date, 19 species are known, mostly from Europe and North America, but five species have been described from Asia (specifically, China, India and Peninsular Malaysia) (Smith 1947; Maas Geesteranus 1980; Perry 2002; Grgurinovic 2003; Robich 2003; Chew et al. 2014; Aravindakshan and Manimohan 2015; Aronsen and Læssøe 2016; Na 2019; Liu et al. 2021).

The circumscription of subsections within sect. Calodontes is problematic. Initially, Smith (1947) divided sect. Calodontes into two subsections, Granulatae and Ciliatae, according to whether the cheilocystidia were smooth or not, but this system was not widely adopted because most of the species have previously been classified in other sections of Mycena on account of the red, yellow or orange basidiomata, coloured lamellar edge and echinulate or diverticulate cheilocystidia, pleurocystidia, pileipellis or stipitipellis (Maas Geesteranus 1980, 1992a, 1992b; Perry 2002; Grgurinovic 2003; Robich 2003; Harder et al. 2010; Chew et al. 2014). Based on the lamellar edge colour, spore amyloid reaction and cystidial features, a widely accepted subsectional classification of sect. Calodontes was proposed by Maas Geesteranus (1980) and subsequent taxonomists (Grgurinovic 2003; Harder et al. 2010; Chew et al. 2014). The primary criteria for segregation were dominated by microcharacters: subsect. Purae (Konrad & Maubl.) Maas Geest. with amyloid spores and colourless pleuro- and cheilocystidia; subsect. Violacellae Sing. ex Maas Geest. with inamyloid spores and no pleurocystidia; and subsect. Marginatae J.E. Lange with amyloid spores and pleurocystidia and cheilocystidia with purplish-brown contents (Maas Geesteranus 1980; Grgurinovic 2003; Harder et al. 2010; Chew et al. 2014). Although the infrasectional classification of Maas Geesteranus (1980) is generally accepted, phylogenetic analyses have provided only weak support because subsect. Purae and subsect. Violacellae are polyphyletic (Perry 2002; Grgurinovic 2003; Robich 2003; Harder et al. 2010, 2012, 2013; Chew et al 2014; Na 2019). In studying Mycenapura (Pers.) P. Kumm., the type of subsect. Purae, Maas Geesteranus (1992a, 1992b) proposed eight forma based on pileus colour. However, 11 clades have been resolved amongst materials collected from Europe and the Americas, which suggests that there may be additional undescribed taxa in subsect. Purae (Harder et al. 2013).

Including our recent description of M.yuezhuoi Z.W. Liu, Y.P. Ge & Q. Na from Kunyushan National Nature Reserve (Yantai, Shandong Province), five species of Mycenasect.Calodontes have been previously recorded in China (Li et al. 2015; Na 2019; Liu et al. 2021). In this paper, we propose an additional four new species classified in sect. Calodontes from the temperate zone of northeast China. The four new species share a unique set of striking morphological characters and contribute to an improved understanding of the classification of sect. Calodontes.

Materials and methods

Morphological observations

Thirteen fungal specimens were examined in this study, which were mainly collected in coniferous forests and some from mixed broadleaf-conifer forests in 2021. Macrocharacters were recorded from fresh specimens. Colour codes in descriptions follow those of Kornerup and Wanscher (1978). Microcharacters were observed from tissues sampled from dried specimens and rehydrated with 5% potassium hydroxide (KOH) and stained with Congo red (1% [w/v] aqueous solution), if necessary, using a Lab A1 microscope (Carl Zeiss AG, Jena, Germany). The amyloid reaction was tested with Melzer’s Reagent (Clémençon et al. 2004; Horak 2005). Twenty basidiospores were measured per specimen. For the holotype, 40 basidiospores from different basidiomata were selected for measurement. Basidiospore statistics are expressed as (a/b/c) (d)e-f-g (h) × (i)j-k–l (m) μm [Q = (n)o-p (q), Q = r ± s], where a–c represent a basidiospores of b basidiomata from c specimens measured; d and h are the minimum and maximum length (5% extremum), respectively, e and g indicate the range of values for the remaining 90% of the spores and f is the average length; width (i–m) and Q values (n–q) are expressed in a similar manner; and r and s are the average Q value and its standard deviation, respectively (Ge et al. 2021; Liu et al. 2021; Na et al. 2021; Na et al. 2022). The measurement of basidia, cystidia and other characters were each based on 20 observations. All specimens have been deposited in the Fungarium of the Fujian Academy of Agricultural Sciences (FFAAS).

DNA extraction, PCR, cloning and DNA sequencing

The Plant Genomic DNA Kit (CoWin Biosciences, Beijing, China) was used to isolate total genomic DNA from dried specimens in accordance with the manufacturer’s instructions. Three nuclear loci were sequenced, comprising the internal transcribed spacer (ITS), RNA polymerase II largest subunit (rpb1) and translation elongation factor-1 alpha (tef1). The primer pairs ITS1/ITS4, rpb1Mp_f1/rpb1Mp_r1 and tEFMp_f2/ tEFMp_r2 were selected to amplify ITS, rpb1 and tef1, respectively (White et al. 1990; Harder et al. 2013; Yu et al. 2020). The PCR reactions were performed in a total volume of 25 µl containing 2 µl DNA template, 1 µl for each primer, 8.5 µl nuclease-free H₂O and 12.5 µl 2× Utaq PCR MasterMix (ZomanBio, Beijing, China). The PCR protocol for amplification of the ITS region was as follows: 94 °C for 4 min, then 34 cycles of 94 °C for 45 s, 52 °C for 45 s and 72 °C for 1 min, with a final extension of 72 °C for 10 min (Na et al. 2022). The PCR protocol for amplification of the rpb1 and tef1 regions followed that of Harder et al. (2013): 94 °C for 60 s, then 10 cycles of 94 °C for 35 s, 53 °C for 45 s and 72 °C for 45 s; then 25 cycles of 94 °C for 35 s, 56 °C for 45 s, 72 °C for 45 s and final extension of 72 °C for 10 min. The PCR products were purified by gel electrophoresis or filter membrane and subjected to Sanger dideoxy sequencing by the Beijing Genomics Institute (Beijing, China).

Phylogenetic analysis

A combined ITS, rpb1 and tef1 dataset was analysed to infer relationships of the new taxa with other members of sect. Calodontes. We used sequences included in previous studies of sect. Calodontes and from members of the most closely-related section deposited in the GenBank database, which were mainly submitted by Harder et al. (2013), Osmundson et al. (2013), Chew et al. (2014) and Liu et al. (2021). For the analysis, representative species of Mycenasect.Supinae Konrad & Maubl., which is closely related to sect. Calodontes, were selected as the outgroup (Osmundson et al. 2013; Na and Bau 2019). Sequences for each DNA region (ITS, rpb1 and tef1) were aligned in MAFFT version 7 online and the aligned matrices were manually checked with BIOEDIT 7.2.5.0 (Hall 1999; Kuraku et al. 2013; Katoh et al. 2019). The best-fit substitution model for each gene partition was determined with MODELTEST 2.3, based on the Akaike Information Criterion (Posada and Crandall 1998). Maximum Likelihood (ML) analysis was conducted by raxmlGUI 2.09 (Edler et al. 2020). The phylogenetic analysis was performed by a single analysis with six partitions (ITS1, 5.8S, ITS2, rpb1 exons, tef1 exons, intron of rpb1 + introns of tef1), using the GTRGAMMA model and 1,000 rapid bootstrap (BS) replicates. For Bayesian Inference (BI), two runs of six chains were run for 15,000,000 generations and sampled every 10,000 generations by MrBayes 3.2.6. At the end of the run, the average deviation of split frequencies was 0.007821, ESS (effective sample size) was 1300.3 and the average Potential Scale Reduction Factor (PSRF) parameter values (excluding NA and > 10.0) = 1.000 and the “sump” and “sumt” commands were used to summarise sampled parameters with 25% burn-in (Ronquist and Huelsenbeck 2003).

Results

Phylogenetic relationships

The dataset consisted of 192 sequences, comprising 39 newly-generated sequences (13 ITS, 13 rpb1 and 13 tef1) and 153 sequences (61 ITS, 46 rpb1 and 46 tef1) downloaded from GenBank. In total, 74 accessions of 19 species were included in the dataset. Detailed information for all sequences is presented in Table 1. The aligned dataset contained 1459 nucleotide sites including gaps (229 sites for ITS1, 159 sites for 5.8S, 177 sites for ITS2, 55 sites for rpb1 exons, 295 sites for tef1 exons, 544 sites for intron of rpb1 + introns of tef1), of which 1146 were conserved, 257 were parsimony-informative and 56 were variable, but parsimony-uninformative. For Bayesian Inference (BI), the selected models for each DNA region of the concatenated dataset were as follows: HKY+G for ITS1 and intron of rpb1 + introns of tef1, JC for 5.8S and rpb1 exons, HKY+I+G for ITS2 and SYM+I+G for tef1 exons. The BI and ML analyses resulted in almost identical topologies; thus, the BI topology is presented as a master tree (Fig. 1).

Table 1.

Specimens used in phylogenetic analysis and GenBank accession numbers.

No.	Species	Specimen voucher	GenBank accession numbers			Locality	Reference
			ITS	rpb1	tef1
1.	Mycenaaff.pura	TL8052	FN394623	KF723687	KF723641	Ecuador	Harder et al. (2010, 2013)
2.	M.aff.pura	TL9433	FN394622	KF723688	KF723642	Ecuador	Harder et al. (2010, 2013)
3.	M.aff.pura	TL9450	KJ144653	KF723689	KF723643	Ecuador	Harder et al. (2010, 2013)
4.	M.aff.pura	TL9678	FN394621	KF723690	KF723644	Ecuador	Harder et al. (2010, 2013)
5.	M.arcangeliana	252b	JF908401	–	–	Spain	Osmundson et al. (2013)
6.	M.arcangeliana	252f	JF908402	–	–	Spain	Osmundson et al. (2013)
7.	M.cahaya	ACL134	KF537248	–	–	Malaysia	Chew et al. (2014)
8.	M.cf.pura I	CBH039	FN394588	KF723680	KF723634	Denmark	Harder et al. (2010, 2013)
9.	M.cf.pura II	CBH105	FN394581	KF723671	KF723625	Denmark	Harder et al. (2010, 2013)
10.	M.cf.pura II	CBH169	FN394579	KF723672	KF723626	Denmark	Harder et al. (2010, 2013)
11.	M.cf.pura II	CBH366	FN394572	KF723673	KF723627	Denmark	Harder et al. (2010, 2013)
12.	M.cf.pura II	CBH404	FN394566	KF723674	KF723628	Denmark	Harder et al. (2010, 2013)
13.	M.cf.pura III	CBH019	FN394605	KF723675	KF723629	Denmark	Harder et al. (2010, 2013)
14.	M.cf.pura III	CBH022	FN394574	KF723676	KF723630	Denmark	Harder et al. (2010, 2013)
15.	M.cf.pura III	KK	FN394606	KF723677	KF723631	Slovakia	Harder et al. (2010, 2013)
16.	M.cf.pura IV	CBH410	FN394595	KF723667	KF723621	Denmark	Harder et al. (2010, 2013)
17.	M.cf.pura IV	JV06979	FN394585	KF723668	KF723622	Denmark	Harder et al. (2010, 2013)
18.	M.cf.pura IV	TL4571	FN394583	KF723669	KF723623	Denmark	Harder et al. (2010, 2013)
19.	M.cf.pura IV	TL12786	FN394591	KF723670	KF723624	Sweden	Harder et al. (2010, 2013)
20.	M.cf.pura V	CBH226	FN394604	KF723664	KF723618	Denmark	Harder et al. (2010, 2013)
21.	M.cf.pura V	TL5614	FN394602	KF723666	KF723620	Denmark	Harder et al. (2010, 2013)
22.	M.cf.pura VI	BAP132	FN394561	KF723660	KF723614	USA	Harder et al. (2010, 2013)
23.	M.cf.pura VIII	CBH216	FN394598	KF723662	KF723616	Denmark	Harder et al. (2010, 2013)
24.	M.cf.pura VIII	CBH402	FN394599	KF723663	KF723617	Denmark	Harder et al. (2010, 2013)
25.	M.cf.pura IX	CBH166	FN394607	KF723701	KF723655	Denmark	Harder et al. (2010, 2013)
26.	M.cf.pura IX	CBH358	FN394608	KF723702	KF723656	Denmark	Harder et al. (2010, 2013)
27.	M.cf.pura IX	CBH367	KF913022	KF723703	KF723657	Denmark	Harder et al. (2013)
28.	M.cf.pura IX	CBH371	KF913023	KF723704	KF723658	Denmark	Harder et al. (2013)
29.	M.cf.pura X	BAP165A	FN394563	KF723698	KF723652	USA	Harder et al. (2010, 2013)
30.	M.cf.pura XI	CBH187	FN394564	KF723678	KF723632	Sweden	Harder et al. (2010, 2013)
31.	M.cf.pura XI	CBH386	FN394565	KF723679	KF723633	Denmark	Harder et al. (2010, 2013)
32.	M.diosma	CBH400	FN394617	KF723699	KF723653	Denmark	Harder et al. (2010, 2013)
33.	M.diosma	LK1191/2000	FN394619	KF723700	KF723654	Germany	Harder et al. (2010, 2013)
34.	M.dura	10315	FN394560	KF723694	KF723648	Austria	Harder et al. (2010, 2013)
35.	M.lammiensis	TUR165927	FN394552	KF723697	KF723651	Finland	Harder et al. (2010, 2013)
36.	M.meliigena	39	JF908423	–	–	Italy	Osmundson et al. (2013)
37.	M.meliigena	39d	JF908429	–	–	Italy	Osmundson et al. (2013)
38.	M.pearsoniana	CBH068	FN394614	KF723691	KF723645	Germany	Harder et al. (2010, 2013)
39.	M.pearsoniana	JV06890	FN394612	KF723692	KF723646	Denmark	Harder et al. (2010, 2013)
40.	M.pearsoniana	LK880/2002	FN394613	KF723693	KF723647	Germany	Harder et al. (2010, 2013)
41.	M.pelianthina	CBH015	FN394549	KF723695	KF723649	Denmark	Harder et al. (2010, 2013)
42.	M.pelianthina	CBH016	FN394547	KF723696	KF723650	Denmark	Harder et al. (2010, 2013)
43.	M.polycystidiata	FFAAS0417 Holotype	ON427731	ON468456	ON468469	China	This study
44.	M.polycystidiata	FFAAS0418	ON427732	ON468457	ON468470	China	This study
45.	M.polycystidiata	FFAAS0421	ON427733	ON468458	ON468471	China	This study
46.	M.polycystidiata	FFAAS0422	ON427734	ON468459	ON468472	China	This study
47.	M.pseudocorticola	124a	JF908386	–	–	Italy	Osmundson et al. (2013)
48.	M.pura	IS10/11/2000	FN394611	–	–	USA	Harder et al. (2010)
49.	M.puraf.lutea	DB2005/152	FN394603	–	–	Denmark	Harder et al. (2010)
50.	M.rosea	UP2	FN394550	–	–	UK	Harder et al. (2010)
51.	M.rosea	CBH097	FN394556	KF723681	KF723635	Denmark	Harder et al. (2010, 2013)
52.	M.rosea	CBH383	FN394553	KF723682	KF723636	Denmark	Harder et al. (2010, 2013)
53.	M.rosea	CBH409	FN394551	KF723683	KF723637	Germany	Harder et al. (2010, 2013)
54.	M.rosea	TL12393	FN394555	KF723684	KF723638	Denmark	Harder et al. (2010, 2013)
55.	M.rosea	TL12409	FN394557	KF723685	KF723639	Denmark	Harder et al. (2010, 2013)
56.	M.rufobrunnea	FFAAS0414	ON427728	ON468453	ON468466	China	This study
57.	M.rufobrunnea	FFAAS0415	ON427729	ON468454	ON468467	China	This study
58.	M.rufobrunnea	FFAAS0416 Holotype	ON427730	ON468455	ON468468	China	This study
59.	M.seminau	ACL136	KF537250	–	–	Malaysia	Chew et al. (2014)
60.	M.seminau	ACL308	KF537252	–	–	Malaysia	Chew et al. (2014)
61.	M.shengshanensis	FFAAS0424 Holotype	ON427739	ON468464	ON468477	China	This study
62.	M.shengshanensis	FFAAS0425	ON427740	ON468465	ON468478	China	This study
63.	M.sinar	ACL092	KF537247	–	–	Malaysia	Chew et al. (2014)
64.	M.sinar	ACL135	KF537249	–	–	Malaysia	Chew et al. (2014)
65.	M.sinarvar.tangkaisinar	ACL307	KF537251	–	–	Malaysia	Chew et al. (2014)
66.	M.subulata	FFAAS0419	ON427735	ON468460	ON468473	China	This study
67.	M.subulata	FFAAS0420	ON427736	ON468461	ON468474	China	This study
68.	M.subulata	FFAAS0423 Holotype	ON427737	ON468462	ON468475	China	This study
69.	M.subulata	FFAAS0426	ON427738	ON468463	ON468476	China	This study
70.	M.supina	128a	JF908388	–	–	Italy	Osmundson et al. (2013)
71.	M.yuezhuoi	FFAAS0344	MW581490	MW868166	MW882249	China	Liu et al. (2021)
72.	M.yuezhuoi	FFAAS0345	MW581491	MW868169	MW882250	China	Liu et al. (2021)
73.	M.yuezhuoi	FFAAS0346	MW581492	MW868168	MW882251	China	Liu et al. (2021)
74.	M.yuezhuoi	FFAAS0347	MW581493	MW868167	MW882252	China	Liu et al. (2021)

Figure 1.

Bayesian Inference analysis of Mycenasect.Calodontes with ITS, rpb1 and tef1 sequence data. Species in Mycenasect.Supinae served as outgroup. Bootstrap values (BS) from Maximum Likelihood ≥ 75 and Bayesian posterior probabilities (BPP) ≥ 0.95 are shown on each branch (BS/BPP). The new species are marked in red.

The phylogenetic analysis revealed that sect. Calodontes was strong support (BS/Bayesian posterior probability [BPP] = 100/1.00) (Fig. 1). Fifteen species and eleven M.pura complex clades within sect. Calodontes were retrieved. Four new species were resolved as monophyletic, each with strong support: M.polycystidiata (BS/BPP = 100/1.00), M.rufobrunnea (BS/BPP = 100/1.00), M.shengshanensis (BS/BPP = 90/1.00) and M.subulata (BS/BPP = 100/1.00). A sister relationship between M.shengshanensis and M.pearsoniana Dennis ex Singer was well supported. Mycenasubulata was resolved as sister, but genetically distant from M.pearsoniana and M.shengshanensis clade. In addition, the sister relationship of Mycenapolycystidiata and M.rufobrunnea were unresolved.

Taxonomy

. Mycena polycystidiata

Z.W. Liu, Y.P. Ge, L. Zou & Q. Na, sp. nov.

314F9605-EDAA-5568-B959-48406818050D

MycoBank No: 843977

Figs 2 , 3 , 4 , 5

Figure 2.

Basidiomata of Mycenapolycystidiata Z.W. Liu, Y.P. Ge, L. Zou & Q. Na a, bFFAAS0422c, dFFAAS0417, holotype e–gFFAAS00421hFFAAS0418 Scale bars: 10 mm (a–h). Photographs a–e, h by Qin Na f, g by Yupeng Ge.

Figure 3.

Microscopic features of Mycenapolycystidiata (FFAAS0417, holotype) a–f basidiospores g basidia h–l cheilocystidia m–r pleurocystidia s pileipellis and hypodermium t lamellar trama u stipitipellis and caulocystidia. Scale bars: 5 μm (a–f); 10 μm (g); 30 μm (h–r); 40 μm (s–u).

Figure 4.

Morphological features of Mycenapolycystidiata (FFAAS0417, holotype) a basidiomata b basidia c basidiospores d pleurocystidia e cheilocystidia f stipitipellis and caulocystidia g pileipellis and hypodermium. Scale bars: 10 mm (a); 10 μm (b–g). Drawings by Zewei Liu.

Figure 5.

Pleurocystidia of MycenapolycystidiataaFFAAS0422bFFAAS0417, holotype cFFAAS0418dFFAAS0421. Scale bars: 25 μm (a–d).

Diagnosis.

Pileus greyish-rose, umbo brownish-orange, hygrophanous. Stipe pubescent. Pleurocystidia polymorphic in shape. Stipitipellis a cutis, with numerous projecting hyphae.

Holotype.

China. Heilongjiang Province: Liangshui National Nature Reserve, Yichun City, 47°12'74"N, 128°52'86"E, 20 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0417 (collection number MY0633).

Etymology.

Refers to the variable shape of pleurocystidia.

Description.

Pileus 14–31 mm in diam., campanulate to hemispherical when young, plano-convex with age, with obtuse umbo at centre, margin slightly revolute, at times cracked at mature; umbo brownish-orange (7C3–7C5), disc purplish-grey (13C2, 14B2, 14C2), reddish-grey (12B2, 12C2) to greyish-rose (12B3), near margin reddish-grey (12D2), greyish-ruby (12D3) or purplish-grey (13D3), margin whitish; striate none or indistinct, greyish-ruby (12E3–12E4), towards the centre up to 1/3 diam.; surface dry and rugose, hygrophanous, generally tomentose. Context white, 2 mm thick, fragile. Lamellae emarginate, slightly decurrent when old, 20–28 reaching the stipe, 1–2 tiers of lamellulae, white, irregularly intervenose, edge concolorous, wavy. Stipe 34–73 × 3–7 mm, central, cylindrical, base occasionally compressed with age; apex violet brown (11E3–11E4, 11F4), greyish-ruby (12E4), lower part brownish-grey (11D2, 11E2) to greyish-brown (11D3, 11E3) or purplish-grey (13C2), fragile, hollow; apex to middle densely pubescent, sparser towards base; whitely villose at base. Odour strongly raphanoid, taste indistinct.

Basidiospores (130/5/4) (6.4)6.7–7.4–8.3(8.8) × (3.2)3.5–3.9–4.3(4.6) μm [Q = (1.62)1.72–2.05(2.18), Q = 1.90 ± 0.11] [holotype (70/2/1) (6.7)6.9–7.6–8.5(8.7) × (3.4)3.6–4.0–4.4(4.6) μm, Q = (1.71)1.76–2.05(2.13), Q = 1.90 ± 0.09], elongated ellipsoid to cylindrical, colourless, smooth, thin-walled, amyloid. Basidia 21–31 × 6–8 μm, 4-spored, clavate, hyaline, sterigmata approximately 4 μm in length. Cheilocystidia thin-walled, hyaline, differs in two shapes, mainly utriform, 50–65 × 20–31 μm, some subclavate, 54–78 × 14–19 μm. Pleurocystidia abundant, thin-walled, hyaline, multi-shaped: lanceolate and mostly round to blunt apices, 37–81 × 12–20 μm, lanceolate and acute apices, 51–87 × 14–22 μm, elliptical, 30–86 × 12–31 μm, ovate and acute apices, 49–71 × 15–24 μm, ovate and mostly round to blunt apices, 49–73 × 16–22 μm. Pileipellis a cutis composed of four to five layers cylindrical cells, 51–81 × 4–5 μm, smooth and thin-walled; terminal cells cylindrical or fusiform, 50–69 × 3–22 μm, thin-walled, hyaline. Hypodermium formed by fusiform to subglobose hyphae, 32–69 × 18–54 μm, thin-walled, hyaline. Lamellar trama subregular, dextrinoid. Stipitipellis a cutis composed of cylindrical hyphae 5–8 μm in diam., smooth, thin-walled, with numbers of projecting hyphae 2–6 μm in diam.; caulocystidia 29–74 × 6–19 μm, clavate or fusiform, thin-walled, smooth, hyaline. Clamps present in all tissues.

Habitat.

Scattered on the litter layers in Pinuskoraiensis and Larixgmelinii mixed forests.

Known distribution.

Heilongjiang Province, China.

Additional material examined.

China. Heilongjiang Province: Liangshui National Nature Reserve, Yichun City, 47°12'82"N, 128°52'94"E, 20 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0418 (collection number MY0634); same location, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0421 (collection number MY0659); same location, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0422 (collection number MY0661).

Notes.

Macroscopically, Mycenaluteovariegata Harder & Læssøe and M.pura resemble M.polycystidiata in pileus colour, but the latter possesses more typically utriform cheilocystidia and uncontracted pleuro- and cheilocystidia (Perry 2002; Robich 2003; Harder et al. 2013; Aronsen and Læssøe 2016; Na 2019). Mycenapearsoniana also has a rose to violaceous pileus, but differs from M.polycystidiata in having inamyloid spores and lacking pleurocystidia (Aronsen and Læssøe 2016; Na 2019). Compared with M.polycystidiata, M.sirayuktha Aravind. & Manim. has similar cheilocystidia, but has an obviously greyish-brown striate pileus, inamyloid spores and slightly glutinous pileipellis with finger-like excrescences (Aravindakshan and Manimohan 2015).

The pleurocystidia of M.polycystidiata varied in shape amongst specimens (Fig. 5). In all four specimens, most pleurocystidia were lanceolate and with round to blunt apices, but pleurocystidia with lanceolate and acute apices, elliptical and ovate and acute apices were also observed in FFAAS0417 (Holotype) and FFAAS0418, while elongated lageniform-lanceolate or round apices ovate were detected in FFAAS0421 and FFAAS0422. The multi-shaped pleurocystidia may show a morphological continuum that changes between developmental stages. Nevertheless, the multi-shaped pleurocystidia are unquestionably diagnostic for identification of this species.

. Mycena rufobrunnea

Z.W. Liu, Y.P. Ge & Q. Na, sp. nov.

A5644585-F3C2-536C-B1B0-C0ADB1C6B3C4

MycoBank No: 843978

Figs 6 , 7 , 8

Figure 6.

Basidiomata of Mycenarufobrunnea Z.W. Liu, Y.P. Ge & Q. Na a, bFFAAS0414c, dFFAAS0415e–hFFAAS0416, holotype. Scale bars: 10 mm (a–h). Photographs a–h by Qin Na.

Figure 7.

Microscopic features of Mycenarufobrunnea (FFAAS0416, holotype) a–d basidiospores e basidia f–l cheilocystidia m lamellar trama n pileipellis and hypodermiumo stipitipellis and caulocystidia. Scale bars: 5 μm (a–d); 20 μm (e–o).

Figure 8.

Morphological features of Mycenarufobrunnea (FFAAS0416, holotype) a basidiomata b basidia c cheilocystidia d basidiospores e stipitipellis and caulocystidia f pileipellis and hypodermium. Scale bars: 10 mm (a); 10 μm (b–f). Drawings by Zewei Liu.

Diagnosis.

Pileus dark brown at centre, disc gradually turning paler to reddish-brown to greyish-brown, edge white. Lamellae obviously intervenose. Stipe apex to middle greyish-magenta to dull violet, lower part darker to dark purple or dark magenta. Cheilocystidia utriform, sometimes clavate. Pleurocystidia absent. Caulocystidia clavate or fusiform. Pileipellis with fusiform terminal cells.

Holotype.

China. Jilin Province: Dayangcha, Erdaobaihe Town, Antu County, Yanbian Korean Autonomous Prefecture, 42°20'73"N, 127°56'06"E, 16 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0416 (collection number MY0581).

Etymology.

Refers to reddish-brown pileus.

Description.

Pileus 12–34 mm in diam., hemispherical to convex when young, then plano-convex, sometimes an unclear umbo at centre, margin slightly revolute, acute to subacute, at times cracked at mature; dark brown (8F6–8F8) at centre, disc gradually turning paler to reddish-brown (8D4–8D5, 8E6–8E8) to greyish-brown (8D3) and turning to whitish at margin; striate reddish-brown (8D4–8D5, 8E6–8E8), towards the centre up to 1/3–1/2 diam.; surface humidus when wet. Context white, 1.5 mm thick, fragile. Lamellae adnexed to emarginate, 20–23 reaching the stipe, 1–3 tiers of lamellulae, white, irregularly intervenose, edge concolorous, slightly serrulate. Stipe 19–62 × 2–6 mm, central, cylindrical, apex to middle greyish-magenta (14E4–14E5) to dull violet (16E3–16E4), lower part darker to dark purple (14F4–14F5) or dark magenta (13F3), fragile, hollow, base slightly swollen with whitish villose. Odour raphanoid, taste indistinct.

Basidiospores (80/4/3) (7.1)7.6–8.4–9.2(9.6) × (3.8)4.0–4.5–5.0 μm [Q = (1.73)1.77–1.98(2.05), Q = 1.88 ± 0.07] [holotype (40/2/1) (7.9)8.1–8.6–9.2(9.4) × 4.2–4.6–5.0 μm, Q = (1.73)1.77–1.96(1.98), Q = 1.87 ± 0.06], elongated ellipsoid to cylindrical, colourless, smooth, thin-walled, amyloid. Basidia 24–34 × 7–10 μm, 4-spored, clavate, hyaline, sterigmata 2–3 μm in length. Cheilocystidia thin-walled, hyaline, utriform, sometimes clavate, 23–44 × 7–17 μm, abundant. Pleurocystidia absent. Pileipellis a cutis composed of four to five slightly interwoven layers of cylindrical cells, 44–70 × 4–7 μm, smooth, thin-walled; terminal cells cylindrical or fusiform, 34–65 × 4–17 μm, thin-walled, hyaline. Hypodermium formed by fusiform, subcylindrical to subglobose hyphae, 15–50 × 12–37 μm, thin-walled, hyaline. Lamellar trama subregular, dextrinoid. Stipitipellis a cutis composed of hyphae 3–9 μm in diam., smooth, thin-walled; caulocystidia common in the apex, sparse in the middle and base, 23–76 × 6–14 μm, clavate and fusiform, thin-walled, hyaline, smooth. Clamps present in all tissues.

Habitat.

Scattered on the decayed logs of Acer, Larix, Pinus, Populus, Quercus and Ulmus mixed forests.

Known distribution.

Jilin Province, China.

Additional material examined.

China. Jilin Province: Dayangcha, Erdaobaihe Town, Antu County, Yanbian Korean Autonomous Prefecture, 42°20'72"N, 127°56'08"E, 16 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0414 (collection number MY0579); same location, 16 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0415 (collection number MY0580).

Notes.

Species of sect. Calodontes that are macroscopically similar to Mycenarufobrunnea have been recorded in many regions of the world. Most taxa resemble M.rufobrunnea in pileus colour (Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Chew et al. 2014; Aronsen and Læssøe 2016). Mycenadura Maas Geest. & Hauskn., recorded in Europe, also has a dark brown to greyish-brown pileus, but can be distinguished from M.rufobrunnea in having a white stipe and having pleurocystidia (Robich 2003; Aronsen and Læssøe 2016). Mycenakuehneriana A.H. Sm., which is recorded from the United States and Canada, is distinguished from M.rufobrunnea in that its pileus is pale avellaneous with rose and lilac, almost white when faded and the spores are obviously smaller (5–6 × 2–3 μm) (Smith 1947; Maas Geesteranus 1992a, 1992b). Mycenaclarkeana Grgur. and M.nullawarrensis Grgur., described from Australia, are similar to M.rufobrunnea in having a reddish-brown pileus, but both species have broader spores and possess pleurocystidia (Grgurinovic 2003). Mycenacahaya A.L.C. Chew & Desjardin, M.seminau A.L.C. Chew & Desjardin and M.sinar A.L.C. Chew & Desjardin, known from Malaysia, resemble M.rufobrunnea owing to the brown pileus, but differ in having adnate to subdecurrent lamellae, a yellowish-grey or brownish-orange stem, mucronate cheilocystidia and lack caulocystidia (Chew et al. 2014). Microscopically, utriform or clavate cheilocystidia and absence of pleurocystidia are key characteristics of M.rufobrunnea. Mycenadiosma Krieglst. & Schwöbel has similar cheilocystidia and pleurocystidia are absent or rare, but it has a strongly hygrophanous pileus and a remarkable change in colour (Robich 2003; Aronsen and Læssøe 2016). Mycenapura, M.sirayuktha and M.vinacea Cleland have similar cheilocystidia, but are easily distinguished from M.rufobrunnea by the presence of pleurocystidia (Perry 2002; Grgurinovic 2003; Robich 2003; Aravindakshan and Manimohan 2015; Aronsen and Læssøe 2016; Na 2019).

. Mycena shengshanensis

Z.W. Liu, Y.P. Ge & Q. Na, sp. nov.

53D69B3C-50BD-5DF4-8FBD-BF102F7EE427

MycoBank No: 843979

Figs 9 , 10 , 11 , 12

Figure 9.

Basidiomata of Mycenashengshanensis Z.W. Liu, Y.P. Ge & Q. Na a–dFFAAS0424, holotype e–hFFAAS0425 Scale bars: 10 mm (a–h). Photographs a–c, e–g by Yupeng Ge d, h by Zewei Liu.

Figure 10.

Microscopic features of Mycenashengshanensis (FFAAS0424, holotype) a–e basidiospores f basidia g–r cheilocystidia s lamellar trama t pileipellis and hypodermium u stipitipellis and caulocystidia. Scale bars: 5 μm (a–e); 20 μm (g–r); 40 μm (s–u).

Figure 11.

Morphological features of Mycenashengshanensis (FFAAS0424, holotype) a basidiomata b basidia c basidiospores d cheilocystidia e stipitipellis and caulocystidia f pileipellis and hypodermium. Scale bars: 10 mm (a); 10 μm (b–f). Drawings by Zewei Liu.

Figure 12.

Cheilocystidia of Mycenashengshanensis FFAAS0424, holotype. Scale bars: 10 μm (a).

Diagnosis.

Pileus brown to violet-brown at centre, disc light brown to dull red. Cheilocystidia clavate with slightly inflated apex, thick-walled. Pleurocystidia absent. Caulocystidia clavate with tapered apices, apex to middle thick-walled. Scattered to gregarious under Larixgmelinii.

Holotype.

China. Heilongjiang Province: Shengshan National Nature Reserve, Heihe City, 49°37'45"N, 126°47'39"E, 23 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0424 (collection number MY0686).

Etymology.

Refers to the type locality.

Description.

Pileus 13–26 mm in diam., when young parabolic to convex, with obtuse umbo at centre, then plano-convex, margin wavy and revolute, at times cracked at mature; centre light brown (7D5–7D6), brown (7E4–7E8), dark brown (8F5–8F6), violet brown (11F4–11F6), disc paler to light brown (7D4–7D5), brown (7E5–7E6), greyish-brown (8D3), reddish-brown (8D4, 8E4), brownish-grey (11C2), dull red (11C3), margin whitish; striate indistinct, brownish-orange (7C3), greyish-brown (7D3), reddish-grey (12D2), greyish-ruby (12E3–12E5), towards the centre up to 1/3–1/2 diam.; surface slightly moist, smooth. Context white, 1–2 mm thick, fragile. Lamellae sinuate to subdecurrent, 19–25 reaching the stipe, 1–3 tiers of lamellulae, white, irregularly intervenose, edge concolorous, wavy and slightly serrulate. Stipe 26–42 × 2–4 mm, central, cylindrical, apex reddish-brown (8E4–8E5), greyish-ruby (12E4–12E5), greyish-brown (11F3), violet brown (11F4–11F5), dark ruby (12F4–12F5), lower part paler to brownish-grey (7C2), brownish-orange (7C3), greyish-brown (11E3), greyish-ruby (12E3), base darker to brown (7E5), reddish-brown (8E4–8E5), greyish-brown (11F3), violet brown (11F4–11F5), greyish-ruby (12E3), dark ruby (12F6–12F8), fragile, hollow, base swollen with white fibrils. Odour raphanoid, taste indistinct.

Basidiospores (60/3/2) (5.9)6.1–6.9–8.1(8.7) × 3.4–4.0–4.4(4.7) μm [Q = 1.62–1.93 (1.97), Q = 1.75 ± 0.09] [holotype (40/2/1) 6.1–7.0–8.2(8.7) × 3.4–4.0–4.4(4.7) μm, Q = (1.62)1.65–1.93(1.97), Q = 1.77 ± 0.08], elongated ellipsoid, colourless, smooth, thin-walled, amyloid. Basidia 22–32 × 6–8 μm, 4-spored, clavate, hyaline, sterigmata 3–4 μm in length. Cheilocystidia moderately thick-walled (0.5–0.6 μm), clavate with slightly inflated apex, 25–63 × 6–12 μm, hyaline. Pleurocystidia absent. Pileipellis a cutis composed of three to four layers of cylindrical cells, 24–57 × 3–5 μm, smooth and thin-walled; terminal cells cylindrical, apically narrow, 28–49 μm in length, apex 1–3 μm and base 2–5 μm in diam., thin-walled, hyaline. Hypodermium formed by fusiform to subglobose hyphae, 19–53 × 13–30 μm, thin-walled, hyaline. Lamellar trama subregular, weakly dextrinoid to dextrinoid. Stipitipellis a cutis composed of hyphae 4–9 μm in diam., smooth, thin-walled; caulocystidia 22–61 × 5–20 μm, clavate with tapered apices, apex to middle thick-walled, smooth, hyaline. Clamps present in all tissues.

Habitat.

Scattered to gregarious on the litter layer in Larixgmelinii.

Known distribution.

Heilongjiang Province, China.

Additional material examined.

China. Heilongjiang Province: Shengshan National Nature Reserve, Heihe City, 23 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0425 (collection number MY0687).

Notes.

In sect. Calodontes, M.diosma, M.pearsoniana and M.yuezhuoi also have clavate cheilocystidia with a slightly inflated apex and lack pleurocystidia, similar to M.shengshanensis, but M.diosma differs in pileus characters, M.pearsoniana has inamyloid spores and M.yuezhuoi has a more purple pileus and subcellular lamellar trama (Robich 2003; Aronsen and Læssøe 2016; Na 2019; Liu et al. 2021). Clavate cheilocystidia are also present in M.luteovariegata and M.pura, but these species differ in having pleurocystidia (Perry 2002; Robich 2003; Harder et al. 2013; Aronsen and Læssøe 2016; Na 2019). Macroscopically, several species in sect. Calodontes also have a brown with reddish or violet pileus or stipe (Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Aronsen and Læssøe 2016). Mycenadura, M.kuehneriana and M.nullawarrensis are distinguished by basidiospore size (Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Aronsen and Læssøe 2016). Two species, M.seminau and M.sirayuktha, reported from Southeast Asia, are similar to M.shengshanensis owing to the brown pileus, but they differ in having gelatinised or sometimes mucronate cheilocystidia and caulocystidia have not been observed (Chew et al. 2014; Aravindakshan and Manimohan 2015). Fusiform, obclavate, ovate and clavate cheilocystidia with a subcapitate protuberance were observed occasionally, but clavate cheilocystidia with a slightly inflated apex represented the predominant morphological type in M.shengshanensis (Fig. 12).

. Mycena subulata

Z.W. Liu, Y.P. Ge & Q. Na, sp. nov.

E08A7A12-E21E-5CD0-B4D9-2B1C693B32FC

MycoBank No: 843980

Figs 13 , 14 , 15

Figure 13.

Basidiomata of Mycenasubulata Z.W. Liu, Y.P. Ge & Q. Na a, bFFAAS0419c, dFFAAS0420e–gFFAAS0423, holotype hFFAAS0426 Scale bars: 10 mm (a–h). Photographs a, b, e, f by Yupeng Ge c, d by Qin Na g by Zewei Liu h by Shixin Wang.

Figure 14.

Microscopic features of Mycenasubulata (FFAAS0423, holotype) a–e basidiospores f basidia g–m cheilocystidia n lamellar trama o pileipellis and hypodermium p stipitipellis and caulocystidia. Scale bars: 5 μm (a–e); 10 μm (f); 20 μm (g–p).

Figure 15.

Morphological features of Mycenasubulata (FFAAS0423, holotype) a basidiomata b basidia c basidiospores d cheilocystidia e stipitipellis and caulocystidia f pileipellis and hypodermium. Scale bars: 10 mm (a); 5 μm (c); 10 μm (b, d–f). Drawings by Zewei Liu.

Diagnosis.

Pileus reddish-grey to dull red, slightly hygrophanous. Cheilocystidia thick-walled, slenderly fusiform with distinctly long and narrow protuberance. Stipitipellis a cutis, with projecting hyphae, caulocystidia thick-walled.

Holotype.

China. Heilongjiang Province: Liangshui National Nature Reserve, Yichun City, 47°13'13"N, 128°53'21"E, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0423 (collection number MY0671).

Etymology.

Refers to cheilocystidia with distinctly long and narrow protuberance.

Description.

Pileus 9–32 mm in diam., convex to campanulate when young, hemispherical to applanate with age, margin sometimes wavy, slightly deflexed; at centre dull red (8C3), brownish-grey (8D2), greyish-brown (8D3), reddish-brown (8D4, 8E4–8E5) and dark brown (8F5), disc paler to reddish-grey (8B2, 9B2), brownish-grey (9C2), dull red (9B3, 9C3), greyish-magenta (13D3), margin light brown (7D4), brown (7E4) or dull red (9C3); striate none or indistinct, reddish-brown (8E4–8E5), towards the centre up to 1/5 diam.; surface dry, unclearly rugose or none, margin slightly hygrophanous. Context white, 1 mm thick, fragile. Lamellae sinuate to subdecurrent, 31–33 reaching the stipe, 1–3 tiers of lamellulae, white, irregularly intervenose, edge concolorous, wavy and slightly serrulate. Stipe 27–75 × 2–5 mm, central, cylindrical, apex to middle brownish-orange (7C3), dull red (8C3), brownish-grey (7D2), greyish-magenta (14D3), lower part brownish-grey (8C2), greyish-brown (8D3), reddish-brown (8D4), fragile, hollow, white granular near apex, base slightly swollen with white fibrils. Odour raphanoid, taste indistinct.

Basidiospores (100/5/4) 6.0–6.7–7.3(7.9) × 3.3–3.8–4.3(4.6) μm [Q = (1.61)1.65–1.87(1.90), Q = 1.76 ± 0.07] [holotype (40/2/1) (6.0)6.2–6.6–7.1 × 3.4–3.7–4.0(4.2) μm, Q = 1.65–1.87(1.90), Q = 1.78 ± 0.07], elongated ellipsoid, colourless, smooth, thin-walled, amyloid. Basidia 23–34 × 5–6 μm, 4-spored, clavate, hyaline, sterigmata 2–3 μm in length. Cheilocystidia moderately thick-walled (0.5–0.6 μm), hyaline, narrowly fusiform with long and narrow protuberance, 43–82 × 4–11 μm, protuberance 14–36 × 1–2 μm. Pleurocystidia absent. Pileipellis a cutis composed of three to four layers of cylindrical cells, 20–89 × 3–7 μm, smooth and thin-walled; terminal cells cylindrical, apically narrow, 24–61 μm in length, the apex 3–4 μm and base 4–7 μm in diam., thin-walled, hyaline. Hypodermium formed by fusiform to subglobose hyphae, 21–41 × 17–25 μm, thin-walled, hyaline. Lamellar trama subregular, dextrinoid. Stipitipellis a cutis composed of hyphae 3–8 μm in diam., smooth, thin-walled, with projecting hyphae 3–8 μm in diam.; caulocystidia 29–47 × 6–12 μm, clavate and apices tapered, thick-walled (0.5–0.6 μm), smooth. Clamps present in all tissues.

Habitat.

Scattered on the litter layer in Pinuskoraiensis, Larixgmelinii and Tilia sp. mixed forests.

Known distribution.

Heilongjiang Province, China.

Additional material examined.

China. Heilongjiang Province: Liangshui National Nature Reserve, Yichun City, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0419 (collection number MY0654); same location, 21 August 2021, Zewei Liu, Yupeng Ge, Qin Na and Shixin Wang, FFAAS0420 (collection number MY0657); Heilongjiang Province: Taipinggou National Nature Reserve, Hegang City, 3 September 2021, Shixin Wang, FFAAS0426 (collection number MY0795).

Notes.

Cheilocystidia with a long and narrow protuberance is the key microscopic character that distinguishes M.subulata and is uncommon in sect. Calodontes (Smith 1947; Maas Geesteranus 1992a, 1992b; Grgurinovic 2003; Robich 2003; Chew et al. 2014; Aravindakshan and Manimohan 2015; Aronsen and Læssøe 2016; Na 2019; Liu et al. 2021). Mycenalammiensis Harmaja and M.pelianthina (Fr.) Quél. have similar cheilocystidia, but differ from M.subulata by their broader cheilocystidia with purplish-brown contents and having pleurocystidia (Smith 1947; Robich 2003; Aronsen and Læssøe 2016). The cheilocystidia of M.subcorticalis (Cooke & Massee) Sacc. with a protuberance are similar to those of M.subulata. However, M.subcorticalis has larger and inamyloid spores, a gelatinised pileipellis and a stipitipellis with sparse excrescences (Grgurinovic 2003). More rarely, mucronate cheilocystidia and absence of pleurocystidia have been described for M.pearsoniana and its clay pink pileus is similar to that of M.subulata, but M.pearsoniana differs in having a slightly glutinous pileus when wet and inamyloid spores (Aronsen and Læssøe 2016; Na 2019). Other species that are macroscopically similar to M.subulata, namely M.luteovariegata, M.nullawarrensis and M.pura, can be distinguished by cheilocystidia shape and presence of pleurocystidia (Perry 2002; Robich 2003; Grgurinovic 2003; Harder et al. 2013; Aronsen and Læssøe 2016; Na 2019).

Key to species of sect. Calodontes known worldwide

1	Stipe white	2
–	Stipe coloured	4
2	Pileus white	Mycenasubaquosa
–	Pileus coloure	3
3	Pileus pink and lamellae emarginate, pileipellis without inflated terminal cells	Mycenarosea
–	Pileus brown and lamellae adnate, pileipellis with fusiform, subcylindrical to lageniform terminal cells	Mycenadura
4	Lamellae edge with coloured dots	5
–	Lamellae edge white or without dots	6
5	Caulocystidia present, spores almost broader than 4 μm	Mycenalammiensis
–	Caulocystidia absent, spores almost narrower than 4 μm	Mycenapelianthina
6	Basidiospores inamyloid	7
–	Basidiospores amyloid	10
7	Pleurocystidia absent	8
–	Pleurocystidia present	9
8	Stipitipellis and caulocystidia smooth	Mycenapearsoniana
–	Stipitipellis and caulocystidia with nodulose excrescences	Mycenasubcorticalis
9	Pileipellis gelatinised, caulocystidia absent, cheilo- and pleurocytsidia base uncontracted, disc greyish-red or orange white in pileus	Mycenasirayuktha
–	Pileipellis not gelatinised, caulocystidia present, cheilo- and pleurocytsidia base contracted, disc wood brown or reddish-brown in pileus	Mycenavinacea
10	Pleurocystidia present	11
–	Pleurocystidia absent	16
11	Caulocystidia absent, almost cheilocystidia apically mucronate or subcapitate	Mycenacahaya
–	Caulocystidia present, almost cheilocystidia apically broadly rounded	12
12	Caulocystidia with apical excrescences, spores more than 5.6 μm width	Mycenaclarkeana
–	Caulocystidia without apical excrescences, spores less than 5.6 μm width	13
13	Cheilocystidia base uncontracted	Mycenapolycystidiata
–	Cheilocystidia base contracted	14
14	Stipe brown to dark brown, Qav = 1.5	Mycenanullawarrensis
–	Stipe not brown to dark brown, Qav > 1.5	15
15	Pileus sulphur yellow to reddish-grey, stipe reddish-grey	Mycenaluteovariegata
–	Pileus generally pinkish or purplish, stipe whitish to pinkish-purple	Mycenapura
16	Caulocystidia absent	17
–	Caulocystidia present	18
17	Pileus brown to dark brown, spores weakly amyloid	Mycenaseminau
–	Pileus brownish-orange to greyish-yellow, spores amyloid	Mycenasinar
18	Cheilocystidia slender fusiform, with distinctly long and narrow protuberance	Mycenasubulata
–	Cheilocystidia clavate, utriform, subfusiform, or subcylindrical, with short mucronate or none	19
19	Spores less than 6 μm length	Mycenakuehneriana
–	Spores more than 6 μm length	20
20	Pileus more than 35 mm in diam., lamellae dark brownish-violet to reddish-violet	Mycenadiosma
–	Pileus less than 35 mm in diam., lamellae white	21
21	Lamellar trama subcellular, pileus lilac to purple	Mycenayuezhuoi
–	Lamellar trama subregular, pileus brownish	22
22	Cheilocystidia utriform, sometimes clavate, thin-walled, lamellae adnexed to emarginate	Mycenarufobrunnea
–	Cheilocystidia clavate with slightly inflated apex, thick-walled, lamellae sinuate to subdecurrent	Mycenashengshanensis

Discussion

Maas Geesteranus (1980) proposed that Mycenasect.Calodontes could be divided into three subsections based on the colour of the lamellar edge and the amyloid reaction of the basidiospores. Subsequently, taxonomists have followed this division, but opinions have differed on the diagnostic characters that support this classification (Grgurinovic 2003; Robich 2003; Harder et al. 2010; Chew et al. 2014). Some taxonomists classified the subsections according to the amyloid reaction of basidiospores, cheilocystidia and pleurocystidia contents and presence or absence of pleurocystidia, but the shapes of cheilocystidia and pleurocystidia were not considered (Grgurinovic 2003; Harder et al. 2010; Chew et al. 2014). Robich (2003) also did not consider the shapes of cheilocystidia and pleurocystidia, but the colour of the lamellar edge and cheilocystidia contents were emphasised to distinguish subsections. According to the historical infrasectional classification of sect. Calodontes, M.polycystidiata could be classified in subsect. Purae, whereas M.rufobrunnea, M.shengshanensis and M.subulata cannot be assigned to a subsection owing to their having amyloid spores and lacking pleurocystidia (Maas Geesteranus 1980; Harder et al. 2010).

Phylogenetic reconstructions do not fully support recognition of three subsections defined by morphological characters; notably, subsect. Violacellae and subsect. Purae are polyphyletic in the phylogenies (Harder et al. 2010, 2012, 2013). Chew et al. (2014) supported the views of Harder et al. (2010, 2012) and the new taxa proposed by the former authors were not assigned to a subsection. Additionally, subsect. Purae was proved to be polyphyletic in our combined analysis of ITS, rpb1 and tef1 dataset, which also supported analysis, based on single gene region (Harder et al. 2013).

The five taxa of Mycenasect.Calodontes recorded from China show obvious differences in pileus colour and in the shapes of cheilocystidia and pleurocystidia (if present) (Liu et al. 2021). The colour of the pileus includes greyish-rose, reddish-grey, purple, reddish-brown and violet-brown and most show a gradual transition with age. Clavate, obclavate, utriform and fusiform cheilocystidia with a long, narrow protuberance are observed, but pleurocystidia are present only in M.polycystidiata. Forms and variations within M.pura complex had a wide range of pileus colour, but the shape of cheilocystidia was highly similar and could be clearly distinguished from the four new taxa (Robich 2003).

In our phylogenetic analysis, four new species all formed separate clades with high support and had obvious genetic distance from other species in sect. Calodontes. Mycenarufobrunnea is more closely related to the phylogenetic species within M.pura complex by Harder et al. (2013). While the other three new species are significantly more distant from M.pura complex genetically, M.shengshanensis and M.subulata, formed a sister relationship with high support from M.pearsoniana; M.polycystidiata clustered with M.diosma, but is poorly supported.

Based on extensive field work in China, most specimens of sect. Calodontes have been observed in coniferous forests or mixed coniferous-broadleaved forests in early autumn (Na 2019; Liu et al. 2021). Specimens of the four new taxa described in the present study were collected from Changbai Mountain and the Lesser Khinggan Mountains in northeast China from mixed broadleaf-Korean pine (Pinuskoraiensis) forests (Zhao et al. 2004; Wang and Guo 2016). In particular, M.polycystidiata and M.subulata were both distributed in the Liangshui National Nature Reserve on the Lesser Khinggan Mountains, where the dominant forest species is P.koraiensis, mixed with fewer Betula, Tilia, Quercus and Picea individuals (She et al. 2022). Moreover, more specimens were located in the northern region of China with an average temperature not more than 20 °C in August. For example, the average temperature is 16.4 °C in Liangshui National Nature Reserve and 16.3 °C in Shengshan National Nature Reserve (Liu 2017). Therefore, we speculate that members of this section in China prefer the climate types Dwa, Dwb and Dwc according to the Köppen climate classification (Kottek et al. 2006; Wang et al. 2020).

Citation

Liu Z, Ge Y, Zeng H, Cheng X, Na Q (2022) Four new species of Mycena sect. Calodontes (Agaricales, Mycenaceae) from northeast China. MycoKeys 93: 23–56. https://doi.org/10.3897/mycokeys.93.86580

Funding Statement

Natural Science Foundation of Shandong Province (grant No. ZR2020QC001), National Natural Science Foundation of China (grant No. 3190012), Natural Science Foundation of Shandong Province (grant No. ZR2019PC028), Shandong Agricultural Industry Technology System (grant No. SDAIT-07-03).