Hyphodermella tropica Yue Li & S.H. He, sp. nov.

MycoBank: MB846337

Diagnosis—The species is recognized by a grandinioid hymenophore, the presence of encrusted cystidioid hyphal ends, and broad ellipsoid to ovoid basidiospores.

Type—China, Hainan Province, Baoting County, Qixianling Forest Park, on a dead angiosperm branch, 11 June 2016, He 3993 (BJFC 022495, holotype, CFMR, isotype).

Etymology—Refer to the known distribution in tropic China.

Fruiting body—Basidiomes annual, resupinate, widely effused, closely adnate, inseparable from substrate, and coriaceous, first as small patches and later confluent up to 11 cm long, 3 cm wide, and up to 80 μm thick in section. Hymenophore grandinioid, grayish orange (5B4) to brownish orange [5C (4–5)], darkening in KOH, and not cracked upon drying; the margin thinning out, adnate, indistinct, and concolorous with hymenophore surface; and context is grayish orange.

Microscopic structures—Hyphal system monomitic; generative hyphae simple-septate. Subiculum distinct; hyphae colorless, thick-walled, smooth, frequently branched, moderately septate, more or less parallel to the substrate, and 2–4 μm in diameter. Subhymenium distinct, thickening, composed of encrusted cystidioid hyphal ends, and hyphae with masses of crystals; hyphae colorless, slightly thick-walled, smooth, moderately branched and septate, loosely interwoven, and 1.5–3 μm in diameter. Cystidioid hyphal ends present, subcylindrical, colorless, thick-walled, heavily encrusted, mostly embedded, and 20–50 × 6–10 μm (crystals included). Basidia subcylindrical, colorless, thin-walled, smooth, usually with oil drops, with a basal simple septum and four sterigmata, and 15–27 × 4–8 μm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores which are broadly ellipsoid to ovoid, with an apiculus, usually with oil drops, colorless, thin-walled, smooth, IKI–, CB–, 5–6 (−6.5) × (3–) 4–5 (−5.5) μm, L = 5.7 μm, W = 4.4 μm, and Q = 1.23–1.34 (n = 60/2).

Additional specimens examined—China, Guizhou Province, Libo County, Maolan Nature Reserve, on a dead angiosperm branch, 16 June 2016, He 3808 (BJFC 022307, CFMR); Hainan Province, Baoting County, Qixianling Forest Park, on a dead angiosperm branch, 11 June 2016, He 4004 (BJFC 022506, CFMR).

Notes—Hyphodermella tropica (Figure 6) is characterized by coriaceous basidiomes with a grandinioid hymenophore, the presence of encrusted cystidioid hyphal ends, and broadly ellipsoid to ovoid basidiospores. In the phylogenetic tree (Figure 1), H. tropica formed a distinct lineage sister to H. pallidostraminea Bukharova & Volobuev and H. laevigata. Hyphodermella pallidostraminea from Russia differs from H. tropica by having a smooth to slightly tuberculate hymenophore, not encrusted cystidioid hyphal ends in hymenium, and narrower ellipsoid basidiospores (3–3.5 μm, Crous et al., 2021). Hyphodermella laevigata can be easily distinguished from H. tropica by the smooth hymenophore, the loose texture of the subiculum, and the lack of encrusted cystidioid hyphal ends. Hyphodermella brunneocontexta Duhem & Buyck from France is similar to H. tropica by sharing an odontioid hymenophore, encrusted cystidioid hyphal ends, and ellipsoid to ovoid basidiospores but differs in having a brown context with densely interwoven hyphae (Duhem and Buyck, 2011).

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Figure 6

Hyphodermella tropica [from the holotype He 3933; scale bars: (A) = 1 cm; (B–F) = 10 μm]. (A) Basidiomes; (B) Basidiospores; (C) Basidia; (D) Basidioles; (E) Encrusted cystidioid hyphal ends; (F) Hyphae from subiculum.

Roseograndinia aurantiaca (C.L. Zhao) Yue Li & S.H. He, comb. nov.

MycoBank: MB846338

= Hyphodermella aurantiaca C.L. Zhao, Annales Botanici Fennici 58: 65, 2020. [MB#837949]

= Roseograndinia jilinensis C.C. Chen & Sheng H. Wu, Fungal Diversity 111: 396, 2021. [MB#840765]

Notes—Both H. aurantiaca and R. jilinensis were recently described from China, and are similar to each other by sharing a smooth to tuberculate, reddish hymenophore, a compact context with a thickened subhymenium, the absence of cystidia, and relatively small ellipsoid basidiospores but differ in the size of the basidiospores according to the descriptions (3–4 × 2–2.8 μm of H. aurantiaca vs. 4.6–5.5 × 2.6–3.1 μm of R. jilinensis, Wang and Zhao, 2020; Chen et al., 2021). However, in our phylogenetic tree (Figure 1), the types of the two species clustered in a strongly supported lineage in the Roseograndinia clade (99/93/1) with the ITS sequence similarity reaching 99.5% (3 differences of 600 base pairs). Thus, based on the morphological and molecular evidence, the new combination R. aurantiaca is proposed herein, since the epithet “aurantiaca” has the priority.

Roseograndinia zixishanensis (C.L. Zhao) Yue Li & S.H. He, comb. nov.

MycoBank: MB846339

= Hyphodermella zixishanensis C.L. Zhao, Nordic Journal of Botany 39 (8): e03329, 4, 2021. [MB#839869]

Notes—The species H. zixishanensis was recently described from Yunnan Province, southwestern China, based on morphological and molecular evidence (Wang et al., 2021). In our phylogenetic tree based on a more complete sampling, including many newly described taxa (Figure 1), the species was nested within the Roseograndinia clade, which was strongly supported as a monophyletic clade with three species and independent of Hyphodermella. Morphologically, Roseograndinia zixishanensis has the typical characteristics of the genus by possessing ceraceous basidiomes with a smooth to tuberculate hymenophore, a monomitic hyphal system with simple-septate generative hyphae, and a lack of cystidia (Chen et al., 2021; Wang et al., 2021).

Phlebiopsis cana Yue Li & S.H. He, sp. nov.

MycoBank: MB846340

Diagnosis—The species is recognized by a smooth hymenophore with a gray to brownish gray hymenial surface, the presence of short lamprocystidia and short cylindrical basidiospores, and its growth on bamboo.

Type—China, Hainan Province, Lingshui County, Diaoluoshan Nature Reserve, on a culm of dead bamboo, 2 July 2019, He 5958 (BJFC 030834, holotype).

Etymology—Refer to the gray color of basidiomes.

Fruiting body—Basidiomes annual, resupinate, widely effused, closely adnate, inseparable from the substrate, and coriaceous, first as small patches and later confluent up to 11 cm long, 2 cm wide, and up to 40 μm thick in section. Hymenophore smooth, gray (4C1) to brownish gray (4D2), slightly darkening in KOH, and not cracked upon drying; the margin thinning out, adnate, indistinct, and concolorous with hymenophore surface when juvenile, and darkening with age; and context is gray.

Microscopic structures—Hyphal system monomitic; generative hyphae simple-septate. Subiculum distinct, a compact texture, pale yellowish-brown, and up to 20 μm thick; hyphae colorless to pale yellow, thick-walled, smooth, rarely branched, moderately septate, more or less parallel to the substrate, slightly agglutinated, and 3–4 μm in diameter. Subhymenium indistinct; hyphae colorless, slightly thick-walled, rarely branched, moderately septate, densely interwoven, and 2–3 μm in diameter. Lamprocystidia scattered, subcylindrical to subfusiform, colorless, thick-walled, apically encrusted with small crystals, projecting beyond the hymenium up to 10 μm, and 15–30 × 5–7 μm (crystals included). Basidia clavate, colorless, thin-walled, smooth, with a basal simple septum and four sterigmata, and 12–18 × 3.5–5 μm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores short cylindrical, with an apiculus, colorless, thin-walled, smooth, IKI–, CB–, (4.6–) 4.8–5.6 (−5.8) × 1.8–2 (−2.2) μm, L = 5.4 μm, W = 2 μm, and Q = 2.66–2.77 (n = 60/2).

Additional specimen examined—Sri Lanka, Western Province, Ingiriya, Dombagaskanda Forest Reserve, on a culm dead bamboo, 27 February 2019, He 5728 (BJFC 030595).

Notes—Phlebiopsis cana (Figure 7) is characterized by having thin basidiomes with a gray, smooth hymenophore surface, short lamprocystidia, and cylindrical basidiospores. In the phylogenetic tree (Figure 2), P. cana formed a lineage sister to P. xuefengensis J. Zou, which is an endophyte of Gastrodia elata from China. The descriptions of P. xuefengensis were based on cultures and not standard or comparable with P. cana (Li et al., 2021). Phlebiopsis cylindrospora Y.N. Zhao & S.H. He that was also found on bamboos in China is similar to P. cana by sharing short lamprocystidia and cylindrical basidiospores but differs in having hymenophores turning purple in KOH, generative hyphae encrusted with yellow, resinous granules, and slightly larger basidiospores (5.5–7.5 × 1.8–2.8 μm, Zhao et al., 2021). Another Phlebiopsis species on bamboo from Taiwan, P. yushaniae C.C. Chen & Sheng H. Wu, differs from P. cana by possessing white to cream basidiomes, possessing broadly ellipsoid to subglobose basidiospores (6.9–7.9 × 5.2–6.2 μm), and possessing a lack of cystidia (Chen et al., 2021). Phylogenetically, P. cana, P. cylindrospora, and P. yushaniae are grouped together with strong support values but formed distinct lineages (Figure 2).

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Figure 2

Phylogenetic tree obtained from ML analysis of the ITS-nrLSU sequences of Phlebiopsis. Branches are labeled with parsimony bootstrap values (≥50%, first), likelihood bootstrap values (≥50%, second), and Bayesian posterior probabilities (≥0.95, third). The new species are set in bold and highlighted.

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Figure 7

Phlebiopsis cana [(A, C–F) from the holotype He 5958; (B) from He 5728; scale bars: (A, B) = 1 cm; (C–F) = 10 μm]. (A, B) Basidiomes; (C) Basidiospores; (D) Basidia and a basidiole; (E) Lamprocystidia; (F) Hyphae from subiculum.

Rhizochaete nakasoneae Yue Li, C.C. Chen & S.H. He, sp. nov.

MycoBank: MB846341

Diagnosis—The species is recognized by a smooth hymenophore turning pinkish buff in KOH, the presence of thick-walled lamprocystidia, and broadly ellipsoid to ovoid basidiospores.

Type—China, Hunan Province, Zhangjiajie, Zhangjiajie Forest Park, on a fallen angiosperm trunk, 7 July 2015, He 2291 (BJFC 020746, holotype).

Etymology—Named to honor Dr. Karen K. Nakasone (CFMR, USA), who contributed much to the taxonomy and phylogeny of Rhizochaete.

Fruiting body—Basidiomes annual, resupinate, widely effused, loosely adnate, easily separated from substrate, and membranaceous to pellicular, first as small patches, later confluent up to 4 cm long, 2 cm wide, and up to 120 μm thick in section. Hymenophore smooth, light orange (6A5) to grayish orange (5B5), turning pinkish buff in KOH, not cracked upon drying; the margin thinning out, adnate, fimbriate, sterile, white when fresh, and becoming pale yellow upon drying; hyphal cords are present, brownish yellow, and turning pinkish buff in KOH; and context is pale yellow.

Microscopic structures—Hyphal system monomitic; generative hyphae simple-septate. Subiculum distinct; hyphae colorless, thin- to slightly thick-walled, usually encrusted with crystals, frequently branched and septate, loosely interwoven, and 3–5 μm in diameter. Subhymenium thickening, composed of lamprocystidia and hyphae; hyphae colorless, thin- to slightly thick-walled, smooth, vertically arranged, moderately branched, rarely septate, and 2–3 μm in diameter. Lamprocystidia numerous, metuloid, subfusiform, colorless, thick-walled, heavily encrusted with crystals, embedded or projecting beyond the hymenium up to 25 μm, and 34–50 × 8–14 μm (crystals included), with walls up to 1.5–2 μm. Basidia clavate, colorless, thin-walled, smooth, with a basal simple septum and four sterigmata, and 18–24 × 3.5–5 μm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores broadly ellipsoid to ovoid, with an apiculus, colorless, thin-walled, smooth, usually with one or two oil drops, IKI–, CB–, 2.5–4 × (1.8–) 2–2.5 μm, L = 3.1 μm, W = 2.1 μm, and Q = 1.34–1.59 (n = 60/2).

Additional specimens examined—China, Guangxi Zhuang Autonomous Region, Xing'an County, Mao'ershan Nature Reserve, on an angiosperm stump, 13 July 2017, He 4821 (BJFC 024340, CFMR); Hunan Province, Zhangjiajie, Zhangjiajie Forest Park, on a rotten angiosperm trunk, 17 August 2010, Wu 1008-62 (TNM F0025327); Taiwan, Nantou County, Jenai Township, Aowanda National Forest Recreation Area, on a fallen angiosperm branch, 3 October 2016, WEI 16-383 (TNM F0031055).

Notes—Rhizochaete nakasoneae (Figures 8A, ​,9)9) is characterized by the thin pellicular basidiomes, simple-septate generative hyphae, thick-walled subfusiform cystidia, and small, broadly ellipsoid to ovoid basidiospores. Morphologically and phylogenetically, R. belizensis Nakasone, K. Draeger & B. Ortiz is closely related to R. nakasoneae but differs by having thicker basidiomes, encrusted hyphae, and distribution in Belize (Nakasone et al., 2017). Rhizochaete fissurata C.L. Zhao, recently described from China, formed a sister lineage to R. nakasoneae and R. belizensis but differs from R. nakasoneae in having thicker basidiomes with a cracked hymenophore, thinner cystidia walls (<1 μm), and slightly larger basidiospores (3–4.5 × 2.5–3 μm, Gu and Zhao, 2021). Rhizochaete radicata differs from R. nakasoneae by longer cystidia (60–100 μm) and slightly larger basidiospores (4–5 × 2.5–3 μm, Greslebin et al., 2004).

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Figure 8

Basidiomes of Rhizochaete [scale bars: (A–F) = 1 cm]. (A) R. nakasoneae (He 4821, paratype); (B, C) R. subradicata [(B) He 3213, holotype; (C) He 5561, paratype]; (D, E) R. terrestris [(D) He 7713, holotype; (E) He 6694, paratype]; (F) R. yunnanensis (He 3302, holotype).

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Figure 9

Rhizochaete nakasoneae [from the holotype He 2291; scale bars: (A–E) = 10 μm]. (A) Basidiospores; (B) Basidia; (C) Basidioles; (D) Lamprocystidia; (E) Hyphae from subiculum.

Rhizochaete subradicata Yue Li & S.H. He, sp. nov.

MycoBank: MB846342

Diagnosis—The species is recognized by a smooth hymenophore turning reddish brown in KOH, the presence of long lamprocystidia, and small ellipsoid basidiospores.

Type—China, Yunnan Province, Yongping City, Baotaishan Forest Park, on an angiosperm stump, 27 November 2015, He 3213 (BJFC 021608, holotype).

Etymology—Refer to the morphological similarity and close phylogenetic relationship of R. radicata.

Fruiting body—Basidiomes annual, resupinate, widely effused, loosely adnate, easily separated from substrate, and membranaceous to pellicular, first as small patches, later confluent up to 6 cm long, 3 cm wide, and up to 200 μm thick in section. Hymenophore smooth, light orange (5A5) to grayish orange (5B5), turning reddish brown in KOH, and not cracked upon drying; the margin thinning out, adnate, fimbriate, sterile, white or pale orange when juvenile, and slightly darkening with age; hyphal cords present, brownish yellow, and turning reddish brown in KOH; and context is pale yellow.

Microscopic structures—Hyphal system monomitic; generative hyphae simple-septate. Subiculum distinct, a loose texture; hyphae colorless, slightly thick-walled, smooth, frequently branched and septate, more or less parallel to substrate, and 3–6 μm in diameter. Subhymenium thickening, composed of lamprocystidia and hyphae; hyphae colorless, slightly thick-walled, smooth, more or less vertically arranged, moderately branched and septate, and 2.5–4 μm in diameter. Lamprocystidia numerous, subcylindrical to subfusiform, slightly thick-walled, encrusted with crystals in the upper part, mostly embedded or slightly projecting beyond the hymenium, and 40–75 (−90) × 7–15 μm (crystals included), with walls up to 1.5–2 μm. Basidia clavate, colorless, thin-walled, smooth, with a basal simple septum and four sterigmata, and 25–40 × 4–6 μm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores ellipsoid, with an apiculus, colorless, thin-walled, smooth, usually with one or two oil drops, IKI–, CB–, (3.5–) 3.8–4.5 (−4.8) × 2.2–2.8 μm, L = 4.2 μm, W = 2.4 μm, and Q = 1.64–1.82 (n = 90/3).

Additional specimens examined—China, Guizhou Province, Jiangkou County, Fanjingshan Nature Reserve, on a rotten angiosperm trunk, 11 July 2018, He 5561 (BJFC 026622); Hubei Province, Wufeng County, Houhe Nature Reserve, on a fallen angiosperm trunk, 16 August 2017, He 5086 (BJFC 024604, CFMR); Hunan Province, Dong'an County, Shunhuangshan Nature Reserve, on a rotten angiosperm stump, 13 July 2015, He 2377 (BJFC 020831, CFMR); Jilin Province, Jiaohe County, forestry experimental area, on a fallen angiosperm trunk, 3 September 2017, He 5152 (BJFC 024670, CFMR); Jiangxi Province, Ji'an County, Jinggangshan Forest Park, on a fallen Rhododendron trunk, 11 August 2016, He 4282 (BJFC 023724, CFMR); Liaoning Province, Qingyuan County, Qingyuan forest ecological test station, on a dead angiosperm bark, 26 August 2015, He 2958 (BJFC 022025); Yunnan Province, Lushui County, Gaoligongshan Nature Reserve, on a fallen angiosperm trunk, 30 November 2015, He 3424 (BJFC 021820, CFMR); Yongde County, Daxueshan Nature Reserve, Dabaoshan, on a dead Quercus stump, 27 August 2015, He 2672 (BJFC 021111, CFMR); Yongping County, Baotaishan Forest Park, on a dead angiosperm tree, 27 November 2015, He 3246 (BJFC 021641).

Notes—Rhizochaete subradicata (Figures 8B, ​,C,C, ​,10)10) is characterized by the thin pellicular basidiomes turning reddish brown in KOH, relatively long cystidia with thickened walls, and ellipsoid basidiospores. Morphologically and phylogenetically, R. subradicata is closely related to R. radicata, which differs by having thicker basidiomes and longer cystidia (60–100 μm, Nakasone et al., 1994). Rhizochaete radicata has been reported worldwide (Nakasone et al., 1994, 2017), but here we show that the widely distributed species in China is R. subradicata. Also, the occurrence of R. radicata in India, Japan, and Vietnam needs further study. Rhizochaete grandinosa C.L. Zhao & Z.R. Gu, recently described from Yunnan Province, southwestern China, differs from R. subradicata by having smaller cystidia (24–50 × 4–9 μm) and shorter basidia (14.5–21 μm, Gu and Zhao, 2021).

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Figure 10

Rhizochaete subradicata [from the holotype He 3213; scale bars: (A–D) = 10 μm]. (A) Basidiospores; (B) Basidia and a basidiole; (C) Lamprocystidia; (D) Hyphae from subiculum.

Rhizochaete terrestris Yue Li & S.H. He, sp. nov.

MycoBank: MB846343

Diagnosis—The species is recognized by a discontinuous hymenophore with well-developed hyphal cords, the absence of cystidia, and growth on the ground.

Type—China, Beijing, Haidian District, Yuyuantan Park, on the ground, 12 August 2022, He 7713 (BJFC 038849, holotype).

Etymology—Refer to the habitat on the ground.

Fruiting body—Basidiomes annual, resupinate, widely effused, adnate, on soil or rotten twigs and leaves, membranaceous or pellicular, fragile, the colonies up to 30 × 20 cm, up to 240 μm thick in section. Hymenophore discontinuous, smooth in the developed part, light yellow (4B5) to yellowish orange (4B7), turning pale purple in KOH, not cracked upon drying; the margin thinning out, adnate, fimbriate, and white; hyphal cords well developed, white to pale orange, and turning pale purple in KOH; and context is white.

Microscopic structures—Hyphal system monomitic; generative hyphae simple-septate with single clamps occasionally present. Subiculum distinct; hyphae colorless, thin- to slightly thick-walled, slightly encrusted with fine crystals, frequently branched and septate, more or less parallel to the substrate, and 2.5–7 μm in diameter; Subhymenium indistinct. Cystidia not observed. Basidia subclavate, colorless, thin-walled, smooth, with a basal simple septum and four sterigmata, and 28–38 × 4.5–6.5 μm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores ellipsoid to broadly ellipsoid, with an apiculus, colorless, thin-walled, smooth, usually with two oil drops, IKI–, CB–, (3.8–) 4–5 (−5.2) × 2.5–3.2 (−3.5) μm, L = 4.4 μm, W = 2.9 μm, and Q = 1.47–1.56 (n = 60/2).

Additional specimens examined—China, Beijing, Haidian District, Jiufeng Forest Park, on the ground, 5 August 2020, He 6694 (BJFC 033642, holotype).

Notes—Rhizochaete terrestris (Figures 8D, ​,E,E, ​,11)11) is characterized by the discontinuous basidiomes growing on the ground, well-developed hyphal cords, and the absence of cystidia. Rhizochaete lutea (Sheng H. Wu) C.C. Chen & Sheng H. Wu also lacks cystidia but differs from R. terrestris by the well-developed basidiomes unchanging in KOH, smaller basidia (19–23.5 × 3.7–4.2 μm), slightly narrower basidiospores (2–2.5 μm), and growth on bamboo in tropical areas (Wu, 1990). In the phylogenetic tree, R. terrestris formed a distinct lineage among the strongly supported group (93/83/1, Figure 3) that includes R. radicata and several other newly described species.

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Figure 3

Phylogenetic tree obtained from ML analysis of the ITS-nrLSU sequences of Rhizochaete. Branches are labeled with parsimony bootstrap values (≥50%, first), likelihood bootstrap values (≥50%, second), and Bayesian posterior probabilities (≥0.95, third). New species are set in bold and highlighted.

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Figure 11

Rhizochaete terrestris [from the holotype He 7713; scale bars: (A–D) = 10 μm]. (A) Basidiospores; (B) Basidia; (C) Basidioles; (D) Hyphae from subiculum.

Rhizochaete yunnanensis Yue Li & S.H. He, sp. nov.

MycoBank: MB846344

Diagnosis—The species is recognized by a smooth hymenophore turning reddish brown in KOH and the presence of apically encrusted lamprocystidia, long basidia, and ellipsoid basidiospores.

Type—China, Yunnan Province, Lushui County, Gaoligongshan Nature Reserve, on a fallen angiosperm trunk, 28 November 2015, He 3302 (BJFC 021697, holotype; CFMR, isotype).

Etymology—Refer to the type locality in Yunnan Province, southwestern China.

Fruiting body—Basidiomes annual, resupinate, widely effused, loosely adnate, easily separated from the substrate, and membranaceous to pellicular, first as small patches, later confluent up to 5 cm long, 2 cm wide, and up to 160 μm thick in section. Hymenophore smooth, grayish yellow (4B4) to brownish orange (5B6), turning reddish brown in KOH, and not cracked upon drying; the margin thinning out, adnate, fimbriate, paler than hymenophore surface, and cream; hyphal cords yellow and turning reddish brown in KOH; and context is yellow.

Microscopic structures—Hyphal system monomitic; generative hyphae simple-septate with rare single clamps. Subiculum distinct; hyphae colorless, thin- to slightly thick-walled, smooth, frequently branched, sometimes with H- or Y-connections, frequently septate, loosely interwoven, and 3.5–6 μm in diameter. Subhymenium thickening, composed of lamprocystidia and hyphae, hyphae colorless, thin- to slightly thick-walled, smooth, loosely interwoven, moderately branched, rarely septate, and 1.5–3 μm in diameter. Lamprocystidia is numerous, subfusiform with an obtuse apex, apically encrusted, mostly embedded, and 40–52 × 6–10 μm (crystals included), with walls up to 1–1.5 μm. Basidia clavate, colorless, thin-walled, smooth, with a basal simple septum and four sterigmata, and 33–45 × 4.5–7 μm; basidioles in shape similar to basidia, but slightly smaller. Basidiospores ellipsoid, with an apiculus, colorless, thin-walled, smooth, usually with oil drops, IKI–, CB–, 4.2–5.2 × 2.8–3.2 μm, L = 4.8 μm, W = 3 μm, and Q = 1.6 (n = 30/1).

Notes—Rhizochaete yunnanensis (Figures 8F, ​,12)12) is characterized by thin basidiomes turning reddish brown in KOH, apically encrusted thick-walled cystidia, and long basidia. In the phylogenetic tree (Figure 3), R. yunnanensis is the sister to R. violascens (Fr.) K.H. Larss., which differs in having a violaceous hymenophore and clamped generative hyphae and lacking cystidia (Eriksson and Ryvarden, 1973). Rhizochaete subradicata is similar to R. yunnanensis by sharing similar-sized basidia and basidiospores but differs in having larger cystidia (40–75 × 7–15 μm) with more proportions of the length encrusted.

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Figure 12

Rhizochaete yunnanensis [from the holotype He 3302; scale bars: (A–E) = 10 μm]. (A) Basidiospores; (B) Basidia; (C) Basidioles; (D) Lamprocystidia; (E) Hyphae from subiculum.