Species of Hymenochaete (Hymenochaetales, Basidiomycota) on bamboos from East Asia, with descriptions of two new species Nie, Ting Tian, Yan Liu, Shi-Liang Yang, Jiao He, Shuang-Hui MycoKeys 2017 20 51 65 MB819604 S. H. He Agaricomycetes Hymenochaetaceae Hymenochaete CoL Fungi Hymenochaete bambusicola Hymenochaetales 3 54 Basidiomycota species bambusicola  Diagnosis. This species is distinguished by the presence of dendrohyphidia and skeletal hyphae and the preferred substrate of bamboo tissues.  Figure 2. Basidiomes of Hymenochaete bambusicola. A He 4116 (holotype) B He 4121. Scale bars: 1 cm.  Holotype. THAILAND. Chiang Mai Province: Mork Fa, on fallen bamboo, 25 Jul 2016, He 4116 (holotype: BJFC; isotype: MFLU).  Figure 3. Microscopic structures of Hymenochaete bambusicola(drawn from holotype). A Basidiospores B Basidia and basidioles C Dendrohyphidia D Setae E Hyphae from hyphal layer.  Etymology. " Bambusicola" (Lat.) refers to growing on bamboo.  Fruiting body. Basidiomes annual, resupinate, effused, closely adnate, coriaceous, at first as small irregular patches, later confluent up to 50 cm long, up to 200 µmthick. Hymenophore smooth, greyish red [7B(3-6)], brownish orange [7C(3-6)], greyish brown (7D3) to light brown [7D(4-6)], not cracked; margin thinning out, light brown [7D(4-8)] to brown [7E(4-8)], usually darker than the hymenophore surface, velvety, up to 1 mm wide. Tissues darkening in KOH.  Microscopic structures. Hyphal system dimitic. Tomentum absent, cortex and hyphal layer present. Cortex up to 10 µmthick, composed of densely interwoven and agglutinated hyphae, sometimes indistinct. Hyphal layer composed of loosely interwoven skeletal and generative hyphae. Skeletal hyphae dominant, golden yellow to yellowish brown, distinctly thick-walled to subsolid, frequently branched, non-septate, 1-3 µmin diam. Generative hyphae scattered, simple-septate, colorless to pale yellow, thin- to thick-walled, moderately branched, 2-5 µmin diam. Setae scattered to abundant, subulate, yellowish to reddish brown, bearing a thick hyphal sheath and an acute tip, without encrustations or sometime slightly encrusted, originating from the subhymenium or the hyphal layer, (55 -)70-150(-170) x7-11 µm, projecting above the hymenium up to 60 µm. Dendrohyphidia numerous, yellowish brown, bearing a thick-walled stem up to 5 µmwide, with branches up to 10 µmlong. Basidia clavate to subcylindrical, colorless, with 4 sterigmata and a basal simple septum, 15-18 x3-4 µm; basidiolessimilar to basidia but smaller. Basidiospores short cylindrical, slightly curved, colorless, thin-walled, smooth, usually with a small guttula, (4 -)4.5-6 x2 -2.5(-2.8) µm, L = 5.1 µm, W = 2.2 µm, Q = 2.3 (n = 60/2).  Additional specimens examined (paratypes: BJFC & MFLU). THAILAND. Chiang Mai Province: Mork Fa, on fallen bamboo, 25 Jul 2016, He 4121 & 4131. CHINA. Yunnan Province: Jinghong, Virgin Forest Park, on fallen bamboo, 7 Jun 2011, He 652.  Remarks.  Hymenochaete bambusicolabelongs to sect. Hymenochaetesensu  Leger(1998)and is morphologically similar to Hymenochaete tropicaS.H. He & Y.C. Dai. However, Hymenochaete tropicahas a monomitic hyphal system, shorter setae (50-90 x7-11 µm), and dendrohyphidia with shorter branches ( He and Dai 2012). Hymenochaete innexaand Hymenochaete koeljalgiiParmasto also resemble Hymenochaete bambusicola, but differ from the latter species by having simple hyphidia (not or rarely branched) and absence of skeletal hyphae ( Dai 2010, Parmasto et al. 2014). Hymenochaete ceratophoraJob [= Hymenochaete alabastrinaG.A. Escobar ex J.C. Legeror Dichochaete ceratophora(Job) Parmasto] is similar to Hymenochaete bambusicolaby having a dimitic hyphal system with thick-walled, branched dichohyphae, numerous dendrohyphidia and short cylindrical basidiospores; however, the former species can be distinguished from the latter by having shorter setae (60-110 x6-10 µm), crystals in hymenium and subhymenium and a distribution in Mesoamerica and South America on unknown substrates (  Leger1998, Parmasto 2000). Hymenochaete tasmanicaMassee ( sect. Hymenochaete) is somewhat similar to Hymenochaete bambusicolaby having dendrohyphidia; however, Hymenochaete tasmanicalacks skeletal hyphae, has a stratified subhymenium and grows on angiosperm substrates (  Leger1998). In the phylogenetic tree, Hymenochaete bambusicolaformed a fully supported clade with Hymenochaete innexa, Hymenochaete koeljalgiiand Hymenochaete tropica(Fig. 1).