Psathyrella (Fr.) Quél. is characterized by fragile basidiomata, hygrophanous pileus, brown to black-brown spore print, smooth or rarely subcorniform cheilocystidia and basidiospores fading to greyish in concentrated sulphuric acid (H₂SO₄) (Kits van Waveren 1985; Örstadius et al. 2015). There are records of more than 300 species, including synonyms and subspecies (Fries 1838; Smith 1972; Kits van Waveren 1985; Örstadius & Kundsen 2012). The /pygmaea clade was established in the study of Örstadius et al. (2015), including 11 species, which is characterized by utriform pleurocystidia and abundant cheilocystidia.

Previously 54 species of Psathyrella s.l. were found in China (Chiu 1973; Bi et al. 1985, 1987; Bi 1991; Wang & Bau 2014; Yan & Bau 2017, 2018a, 2018b; Yan et al. 2019) including eleven species described from the country, but only two species in the /pygmaea clade were recorded. In this paper, a new species and two newly recorded species in the clade were reported, based on morphological characters and the phylogenetic analyses.

Specimens were deposited in the Herbarium of Mycology, Jilin Agricultural University (HMJAU). Macroscopic characteristics of fresh specimens were recorded in the field. Color codes are from Kornerup & Wanscher (1978). Thirty basidiospores, cystidia and basidia in water and 5% aqueous KOH were measured under a microscope. The measurements and Q values are given as (a)b-c(d), in which “a” is the lowest value, “b-c” covers a minimum of 90% of the values and “d” is the highest value. “Q” stands for the ratio of length and width of a spore (Bas 1969; Yu et al. 2020).

DNA was extracted from dried specimens with the NuClean Plant Genomic DNA kit (CWBIO, China). Four regions were generated for the study, including the complete ITS region, about 1 200bp of the LSU nuclear ribosomal DNA, about 1 000bp of translation elongation factor subunit 1 alpha (Tef-1α), and about 430bp of the β-tubulin gene. The sequences of ITS, LSU, Tef-1α and β-tub were amplified respectively by ITS1/ITS4 (White et al. 1990), LR0R/LR7 (Hopple & Vilgalys 1999), EF983F/EF2218R (Örstadius et al. 2015) and B36f/B12r (Nagy et al. 2011). PCR was performed using a touchdown program: 5min at 95°C; 1min at 95°C; 30s at 65°C (add -1°C per cycle); 1min at 72°C; cycle 15 times; 1min at 95°C; 30s at 50°C; 1min at 72°C; cycle 20 times; 10min at 72°C (Yan & Bau 2017). DNA sequencing was done by Genewiz (Suzhou City, China).

Based on the results of BLAST and referring to the researches of the Örstadius et al. (2015) and Yan & Bau (2018a), the ITS, LSU, Tef-1α, and β-tub sequences from the 22 fungal taxa were analyzed, including 9 partitions (ITS1, 5.8s, ITS2, LSU, Tef 1st, Tef 2nd, Tef 3rd, Tub 1st, and Tub 2nd). The details are presented in Table 1. Sequences were aligned by the online version of the multiple sequence alignment program MAFFT v7 (Katoh & Standley 2013) and were manually adjusted in BioEdit v7.1.3.0 (Hall 1999). Phylogenetic analyses were conducted using Bayesian Inference (BI) in MrBayes v3.2.6 (Ronquist & Huelsenbeck 2003) and Maximum Likelihood (ML) in IQtree v1.5.6 (Nguyen et al. 2014). For BI analyses, gaps were treated as missing data (Örstadius et al. 2015), the best model was selected by MrModeltest v2.3 (Nylander 2004). Four Markov Chains (MCMC) were run for one million generations, sampling every 100th generation. Runs were inspected to make sure the average standard deviation of split frequencies went below 0.01. The first 25% of trees were discarded (Ronquist & Huelsenbeck 2003). ML analyses were executed applying the Ultrafast Bootstrap Approximation with 1 000 replicates.

The new species shares only 95% similarity with P. pygmaea, based on the BLAST results of ITS, and 99% similarity with P. saponacea, based on the BLAST results of LSU. The materials of P. panaeoloides and P. saponacea from China share more than 98% similarity with those from Europe respectively. The Bayesian Inference (BI) and ML bootstrap proportion are shown in Fig. 1. Phylogenetic tree (Fig. 1) shows that the materials are divided into two clades (/Cystopsathyra and /pygmaea), with high statistical support value (BPP=1, Bootstrap≥91). The new species, P. squarrosa, forms an independent lineage in /pygmaea clade and groups together with P. amaura, P. olympiana and P. pygmaea. The materials of P. panaeoloides and P. saponacea from China group together with those from Europe respectively, with high statistical support value (BPP=1 Bootstrap=100).

Psathyrella squarrosa T. Bau & J.Q. Yan, sp. nov. Fig. 2

MycoBank MB824883

Diagnosis: Basidiomata gregarious. Veil subcorniform, evanescent. Spores (4.9-)5.4-6.3× (2.9-)3.4-3.9(-4.4)μm, germ pore present but indistinct. Pleurocystidia utriform, apex obtuse or broadly obtuse, rarely branched, covered by obviously yellow deposition. Veil consisting of oblong-ellipsoid to subglobose cells.

Type: CHINA. Guangdong Province: Shaoguan City, Chebaling National Forest Park, N 24°42′51.38″ E 114°14′20.86″, 5 Jul 2017, Tolgor Bau, Jun-Qing Yan and Qin Na (HMJAU37827).

Gene sequences of ex-type: MH155964 (ITS), MH155961 (LSU), MH161168 (tef-1α) and MH161171 (β-tub).

Etymology: Name refers to the macroscopic characteristics of the veil.

Basidiomata small. Pileus 8.0-22mm, hemispherical to broadly convex, dark brown to red-brown (8C5-8E8), pale at margin (6B4-6C5), hygrophanous, striate up to center. Veil white (7A1), subcorniform, turning pale brown (7B5-7C6) as drying, evanescent. Context thin and very fragile, about 1.0mm at center, same color with pileus. Lamellae about 2.0mm broad, close, slightly adnexed, dirty white (7A1-7B1) to pale brown (7C4-7C6) as spores mature, sawtoothed under 20× magnifier. Stipes 25-33×1.5-2.0mm, covered with white fibrils, evanescent, inflated at base. Odour and taste indistinctive. Spore print coffee (7D5-7D6).

Spores (4.9-)5.4-6.3×(2.9-)3.4-3.9(-4.4)μm, Q=1.3-1.8(-2.3), ellipsoid to oblong-ellipsoid, rarely ovoid, in profile slightly flattened on one side, subphaseoliform, pale red-brown in water, pale yellow-brown to taupe in 5% KOH, smooth, 1- or 2-guttulate or without guttula, germ pore present but indistinct, about 1.0μm broad. Basidia 16-18×7.3μm, clavate, hyaline, 4- or 2-spored. Pleurocystidia 29-49×8.5-20μm, utriform, apex obtuse or broadly obtuse, rarely branched, covered by obviously yellow deposition, slightly thick-walled. Cheilocystidia 20-34×7.3-13μm, utriform, apex covered by obviously yellow deposition, slightly thick-walled, or clavate, thin-walled. Caulocystidia 31-56× 7.3-17μm, lageniform with subacute apex or clavate, slightly thick-walled. Trama of gills parallel hyphae. Pileipellis consisted of 1-2 cells deep layer of subglobose cells, 24-40μm broad. Veil consisting of oblong-ellipsoid to subglobose cells, 30-41×24-30μm, with yellow to pale yellow wall, rarely sedimental at surface. Clamps very rare, only present on hyphae of the veil and cortex of stipe.

Habit and habitat: Gregarious on rotten wood in hardwood forest.

Additional specimen examined: Guangdong Province: Shaoguan City, Chebaling National Forest Park, 5 Jul 2017, Tolgor Bau, Jun-Qing Yan and Qin Na (HMJAU37828).

Psathyrella panaeoloides (Maire) Arnolds, Biblthca Mycol. 90: 433 (1982). Fig. 3

Psathyra panaeoloides Maire, Publ. Inst. Bot. Barcelona 3(no. 4): 117 (1937).

Drosophila panaeoloides (Maire) Kühner & Romagn., Fl. Analyt. Champ. Supér. (Paris): 361 (1953).

Pileus 5.0-30mm, hemispherical, flattening in the age, slightly umbo at early age, hygrophanous, reddish brown (9D6-9D7) to pale brown (8C4-8C5), striate up to 1/2. Veil white (7A1), fibrils in young, evanescent. Context 1.0-1.5mm broad at center, same color as pileus. Lamellae moderately to normally closed, adnate, whitish (8A1-8B1) to gray-brown (8C1-8E1), edge white (8A1-8B1) as spores mature. Stipes 15-45×1.0-3.5mm, covered with white fibrils, evanescent.

Spores 6.8-8.8×4.9-5.8μm, Q=1.2-1.8, ovoid to ellipsoid, partly triangular at base, flattened in side view, red-brown in water, brown in 5% KOH, smooth, germ pore distinct, 1.0-1.5μm in broad. Basidia 12-25×7.5-12μm, short clavate, hyaline, 4-spored. Pleurocystidia 29-46(61)×7.3-14(20)μm, utriform, apex obtuse or broadly obtuse, or often subcapitate, rarely with yellow deposits. Cheilocystidia 27-49× 7.3-12μm, similar to pleurocystidia in size and form. Trama of gills irregular. Pileipellis consisted of 2-3 cells deep layer of subglobose cell, 27-37μm broad. Clamps rare, only present on hyphae of cortex of stipe.

Habit and habitat: Scattered on soil in Populus sp.

Specimens examined: Jilin Province: Lushuihe Town, Deer Park, 12 Jul 2010, Tolgor Bau (HMJAU23696); Tibet: Lhasa, 6 Aug 1999, Tolgor Bau (HMJAU551).

Psathyrella saponacea F.H. Møller, Fungi of the Faeröes, Part I: Basidiomyceten: 179 (1945). Fig. 4

Psathyrella coprophila Watling, Notes R. bot. Gdn. Edinb. 31: 146 (1971).

Psathyrella fimetaria Watling, Notes R. bot. Gdn. Edinb. 31: 143 (1971).

Pileus 8.0mm, hemispherical, smooth, hygrophanous, darker brown (8E5-8E6), fading to yellowish brown (7C5-7D5), striate up to 3/4. Context 2.0mm broad at center, same color as pileus. Lamellae 2.0mm broad, moderately to normally closed, adnate, grey brown (8D1-8E1) to dark brown (8D5-8E5), edge white. Stipes 40×1.0-2.0mm, white (8A1-8B1), apex pruinose.

Spores 10-14×5.8-7.8μm, Q=1.6-1.9, ellipsoid to ovoid, red-brown in water, dark brown to blackish brown in 5% KOH, smooth, germ pore distinct, often slightly eccentrical, 1.5μm in broad. Basidia 17-22×10-12μm, short clavate, hyaline, 4-spored. Pleurocystidia 37-51×12-16μm, narrowly utriform to broad, apex obtuse or subcapitate, sometimes bottom side tapering to long or short stipe. Cheilocystidia 27-39×8.5-15μm, abundant, similar to pleurocystidia in form and size, mixed by sphaeropedunculate and clavate marginal cells. Trama of gills irregular. Pileipellis consisted of subglobose cell to ellipsoid, 15-40μm broad. Clamps rare, observed on all hyphae except pileipellis.

Habit and habitat: solitary to scattered on dung of cow.

Specimen examined: Shanxi Province: Xinzhou City, Wutai Mount, 8 Jul 2017, Tolgor Bau and Jun-Qing Yan (HMJUA37935).

Psathyrella pygmaea is very easily confused with P. squarrosa in having similar macroscopic characteristics, slightly thick-walled and utriform pleurocystidia with deposition at apex. But the former has hyphal veil cells and distinct germ-pore (1.0-1.5μm broad) (Kits van Waveren 1985; Örstadius & Kundsen 2012).

Psathyrella squarrosa has subcorniform veil consisting of oblong-ellipsoid to subglobose cells, which is an uncommon characteristic in Psathyrella. Based on the characteristics of the veil, it can be classified into section Cystopsathyra in( Kits van Waveren’s classification system 1985, 1987) or subgenus Cystopsathyra in Smith’s classification system (Smith 1972). The known species described in the section/subgenus are different from P. squarrosa obviously: the spores of P. floridana (Murrill) A.H. Sm. and P. kellermanii (Peck) Singer are over 7.0μm long (Smith 1972); the spores of P. minutisperma A.H. Sm. are less than 5.0μm long (Smith 1972) and the P. sphaerocystis P.D. Orton has bigger spores (7.5-9.0×5.0-5.5μm), obvious germ-pore and fusiform pleurocystidia (Kits van Waveren 1985; Örstadius & Kundsen 2012).

Some other species having similar veil cells can be separated as follows: P. albofloccosa Arenal, M. Villarreal & Esteve-Rav. has thin-walled cystidia, whose spores are longer (over 7.5μm) (Arenal et al. 2003); the pleurocystidia of P. bivelata Contu are absent (Contu 1991); P. coprinoides A. Delannoy, Chiaffi, Courtec. & Eyssart. has pileocystidia and lageniform pleurocystidia (Delannoy et al. 2002); P. globosivelata Gröger is parasitic on deformed fungi, whose spores are longer (over 7.0μm) (Gröger 1986); the pleurocystidia of P. granulosa Arnolds and P. lyckebodensis Örstadius & E. Larss. are fusiform or lageniform (Arnolds 2003; Örstadius et al. 2015); P. tenuicula (P. Karst.) Örstadius & Huhtinen has pileocystidia (Örstadius & Huhtinen 1996).

Psathyrella panaeoloides has utriform cystidia, that’s the reason why Kits van Waveren (1985) classified it into subsect. Lutenses, which can be very easily separated from other species in this subsection, based on its small basidiomata, and the partly triangular at base of spores. P. seymourensis A.H. Sm. and P. senex (Peck) A.H. Sm. share the same macroscopic characteristics with P. panaeoloides, and they are easily confused in field, but the cystidia of P. seymourensis are fusiform (Smith 1972) and slender, and the base of spores of P. senex is not triangular (Örstadius 2007). Psathyrella saponacea is coprophilous. P. fimiseda Örstadius & E. Larss. is also coprophilous and is easily confused with P. saponacea, but P. fimiseda has shorter spores, rarely up to 10μm, and fusiform pleurocystidia (Larsson & Örstadius 2008).

The phylogenetic analysis is consistent with the study of morphology. Psathyrella squarrosa groups with P. amaura, P. olympiana and P. pygmaea in /pygmaea clade, and is independent from them obviously. All of them have thick or slightly thick wall and utriform pleurocystidia. But P. amaura and P. olympiana have hyphal veil cells and their spores are over 7.0μm long (Smith 1972; Kits van Waveren 1985; Örstadius & Kundsen 2012). Psathyrella albofloccosa, P. globosivelata, P. kellermanii, P. lyckebodensis, and P. tenuicula, which have subglobose to globose veil cells, group together in the clade /Cystopsathyra and are distinguished from P. squarrosa easily. The materials of P. panaeoloides and P. saponacea from China group together with those from Europe respectively, with no significant genetic distance.

Key to Psathyrella Related Species

1. Parasitic on deformed fungi∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. globosivelata

1. Grown on the ground, rotten wood or dung∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙2

2. Veil consisting of hyphal cells∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙3

2. Veil consisting of oblong-ellipsoid to subglobose cells∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙10

3. Pleurocystidia fusiform∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙4

3. Pleurocystidia utriform∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙5

4. Pleurocystidia with subcapitate apex∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. seymourensis

4. Pleurocystidia with obtuse apex, rarely forked∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. fimiseda

5. Germ pore indistinct∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. amaura

5. Germ pore distinct∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙6

6. Spores at least partly triangular at base∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. panaeoloides

6. Spores not triangular at base∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙7

7. Spores up to 7.0µm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. pygmaea

7. Spores longer∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙8

8. Spores up to 14µm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. saponacea

8. Spores less than 11.0µm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙9

9. Pleurocystidia usually slightly to distinctly thick-walled∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. olympiana

9. Pleurocystidia thin-walled∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. senex

10. Spores less than 5.0μm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. minutisperma

10. Spores over 5.0μm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙11

11. Spores 5.0-6.0μm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. squarrosa

11. Spores over 6.0μm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙12

12. Pleurocystidia absent∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙13

12. Pleurocystidia present∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙14

13. Spores less than 7.5μm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. floridana

13. Spores over 7.5μm long∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. bivelata

. Pileocystidia present∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙15

14. Pileocystidia absent∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙16

15. Cheilocystidia partly with deposits and weakly thickened walls∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. coprinoides

15. Cheilocystidia without deposits and thin-walled∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. tenuicula

16. Germ pore indistinct or absent, pleurocystidia sometimes capitate∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. lyckebodensis

16. Germ pore distinct, pleurocystidia not capitate∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙17

17. Spores up to 11μm or longer∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙18

17. Spores shorter, less than 8.5μm∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙19

18. Spores 6.0-7.0μm broad∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. kellermanii

18. Spores 4.5-6.0µm broad∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. albofloccosa

19. Pleurocystidia fusiform∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. granulosa

19. Pleurocystidia narrowly lageniform to subutriform∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙∙P. sphaerocystis