Antrodiella descendena (Corner) C.L. Zhao & Y.C. Dai, comb. nov.

Index Fungorum number: IF 646298; MycoBank number: MB 556447; Facesoffungi number: FoF 06040; Figs. 104, 105c, d

Basionym: Tyromyces descendens Corner, Beih. Nova Hedwigia 96: 167 (1989).

Basidiocarp basidiocarps annual, pileate. Pileus semicircular, projecting up to 1 cm, 1.5 cm wide, and 1 cm thick at base. Pileal surface buf to pale brown on drying, smooth, azonate; margin obtuse. Pore surface orange-brown to brown upon drying; pores angular, 4–5 per mm; dissepiments thin. Context cream to yellowish brown, corky, about 2 mm thick. Tubes concolorous with pore surface, corky, up to 8 mm thick. Hyphal system dimitic; generative hyphae with clamp connections; skeletal hyphae IKI–, CB–, present in trama only; tissues unchanged in KOH. Subicular generative hyphae hyaline, thin-walled, occasionally branched, 4.0–5.0 µm diam; skeletal hyphae yellowish brown, thick-walled, with a wide lumen, unbranched, loosely interwoven, 3–4.5 µm diam. Tramal generative hyphae infrequent, hyaline, thin-walled, usually unbranched, 3.0–4.5 µm diam; skeletal hyphae dominant, hyaline, thick-walled with a wide to narrow lumen, unbranched, interwoven, 3.0–5.0 µm diam. Cystidia and cystidioles absent; basidia and basidioles absent. Basidiospores cylindrical, hyaline, thin-walled, smooth, IKI–, CB–, 3.0–3.4(–3.6)×1.0–1.3(–1.5) µm, L=3.16 µm, W=1.12 µm, Q=2.82 (n=30/1).

Material examined: MALAYSIA, Johore, Gunong Panti, 28 April 1941, leg. E.J.H. Corner, E00159582 (E).

Notes: The type specimen of Tyromyces descendens was examined by Hattori (2002) but he did not find basidiospores and treated it as Antrodiella sp. based on a dimitic hyphal system. In the present study, we found the basidiospores by re-examining the type specimen and confirmed that the specimen belongs to Antrodiella. Therefore, we propose a new combination A. descendena although we did not get DNA from the type material. A. americana Ryvarden & Gilb. and A. descendena share basidiospores of similar size (2.5–3.5 × 1.0–1.8 µm). However, the former differs by resupinate basidiocarps and larger-sized pores (1–2 per mm,
Núñez and Ryvarden 2001).

Fig. 104 Microscopic structures of Antrodiella descendena (E00159582, holotype). a Basidiospores. b Hyphae from trama. c Hyphae from context. Scale bar: a =5 μm, b–c =10 μm

Fig. 105 Basidiocarps of Tyromyces minutulus (BJFC017406, holotype) and the combination taxon Antrodiella descendena (holotype). a, b Tyromyces minutulus. c, d Antrodiella descendena. Scale bars: a=0.5 cm, e–f=2 mm