Fuscoporia subchrysea 2020

Fuscoporia subchrysea Q. Chen, F. Wu & Y.C. Dai 2020

MycoBank MB 833961; Facesoffungi number: FoF 07992.

Holotype: China, Hainan Province, Wuzhishan County, Wuzhishan Nature Reserve, on dead bamboo, 15 Nov 2015, Y.C. Dai 16201 (BJFC 020287).

Morphological description

Basidiocarps – Annual, resupinate, inseparable, soft corky and without odor or taste when fresh, becoming corky and light-weight upon drying, up to 18 cm long, 4 cm wide and 1 mm thick at centre. Pore surface fuscous to honey-yellow or fawn, occasionally cracked when dry; sterile margin cinnamon-buff, distinctly paler than pore surface, usually with abundant mycelial setae, up to 1 mm wide; pores more or less circular, 8–9 per mm; dissepiments thin, entire, abundant hymenial setae seen in tube cavities (under anatomical lens). Subiculum reddish brown, corky, very thin, up to 0.2 mm thick. Tubes grayish brown, paler than subiculum, hard corky, up to 0.8 mm long. 

Hyphal structure – Hyphal system dimitic; generative hyphae simple septate; tissue darkening but otherwise unchanged in KOH. 

Subiculum – Generative hyphae rare, hyaline, thin-walled, occasionally branched, frequently simple septate, 2–3.5 μm in diam.; skeletal hyphae dominant, rust-brown, thick-walled with a wide lumen, unbranched, occasionally septate, flexuous, interwoven, 3.5–4 μm in diam.; mycelial setae frequent, dark reddish brown, thick-walled, tapering to apex, present in the subiculum and in the rotten wood cavities, sometimes locally abundant, often in bundles, up to 130 μm long and 6–9 μm in the widest part. 

Tubes – Generative hyphae frequent, mostly present at dissepiment edges and subhymenium, hyaline, thin-walled, occasionally branched and frequently simple septate, 1.5–3 μm in diam, some of them encrusted at dissepiment edges and in hymenium; skeletal hyphae dominant, yellowish brown, thick-walled with a medium or wide lumen, unbranched, aseptate, more or less straight, subparallel along the tubes, 3–4 μm in diam. Hymenial setae frequent, narrowly subulate, mostly originating from tramal hyphae, dark brown, thick-walled, 40–68 × 5–8 μm; basidia barrel-shaped, with four sterigmata and a simple septum at the base, 11–13 × 5–7.5 μm; basidioles dominating in hymenium, capitate, but shorter than basidia. 

Spores – Basidiospores ellipsoid, hyaline, thin-walled, smooth, usually glued in tetrads, sometimes bearing a small guttule, IKI–, CB–, 3.8–4.4(–4.7) × 2.6–3.2(–3.4) μm, L = 4.07 μm, W = 3 μm, Q = 1.31–1.42 (n = 60/2). 

Habitat: dead bamboo.

Distribution: tropical Asia. 

GenBank Accession: ITS：MN816708*；nLSU：MN809997*；RPB2：MN848796*；TEF1：MN848811*

Notes: Fuscoporia subchrysea is characterized by small pores (8–9 per mm), septate skeletal hyphae, long hymenial setae (> 40 μm), presence of mycelial setae and absence of cystidioles. The species may be confused with F. chrysea (Lév.) Baltazar & Gibertoni by the similar resupinate basidiocarps, small pores (9–10 per mm in F. chrysea) and broadly ellipsoid basidiospores.However, F. chrysea has perennial basidiocarps with bright golden yellow pore surface and absence1502of mycelial setae (Ryvarden & Johansen 1980, Ryvarden 2004, Dai 2010). In addition, F.subchrysea and F. chrysea are genetically very distant species (Fig. 2). Fuscoporia bambusae and F.subchrysea are found in tropical Asia, and both species can grow on bamboo. However, pores are bigger in F. bambusae than in F. subchrysea (5–7 per mm vs. 8–9 per mm), and spores are longer in F. bambusae than in F. subchrysea (4.3–5.3 μm vs. 3.8–4.4 μm).

Reference: Chen Q, Du P, Vlasák J et al.2020 – Global diversity and phylogeny of Fuscoporia (Hymenochaetales, Basidiomycota). Mycosphere 11(1), 1477–1513, Doi 10.5943/mycosphere/11/1/10

Basidiocarps of Fuscoporia species. a–b Fuscoporia plumeriae (holotype, Dai 18858). c–d Fuscoporia shoreae (c holotype, Dai 17818, d paratype, Dai 17800). e Fuscoporia subchrysea (holotype, Dai 16201). f Fuscoporia bambusicola (holotype, Cui 8692). g Fuscoporia roseocinerea (holotype, JV 1407/85). Scale Bars = 10 mm.