Hymenochaete subporioides L.W. Zhou & Y.C. Dai, sp. nov.
Index Fungorum number: IF551491; Facesoffungi number: FoF01005; Fig. 2
Etymology: referring to the similarity to Hymenochaete porioides.
Holotype: BJFC011058

Basidiocarps annual, pileate, sometimes attached by a lateral tapering base, imbricate, corky and without odour or taste when fresh, hard corky and brittle when dry. Pilei dimidiate to usually fan-shaped, projecting up to 2.5 cm, 3 cm wide and 4 mm thick at base. Pileal surface cinnamon-buff, yellowish brown to brown,  arrowly concentrically zoned in different shades, tomentose to velutinate; margin acute, convex when dry. Pore surface yellowish brown to dark brown; sterile margin distinct, yellowish brown, up to 1 mm wide; pores circular to angular, 6 – 8 per mm; dissepiments thin, entire. Context orange-brown, up to 3 mm thick, duplex, towards the tomentum separated by two black lines, lower and medium parts hard corky, upper tomentum soft corky. Tubes honey- yellow, paler than pores, up to 1 mm long. Hyphal system monomitic; generative hyphae with simple septa; tissue darkening and slightly swelling in KOH. Contextual hyphae in the lower dense context yellow, thick-walled with a wide lumen, unbranched, loosely interwoven, 3 – 5 μm in diam; hyphae in the two black lines dark brown, distinctly thick-walled with a narrow lumen, strongly agglutinated; hyphae between the two black lines yellow to brown, unbranched, parallel along the black lines, 3 – 4.5 μm in diam; hyphae in the upper tomentum brown, thick-walled with a wide lumen, unbranched, regularly arranged, 3 – 4.5 μm diam. Tramal hyphae varying from pale yellowish and slightly thick-walled to brown and thick-walled with a wide lumen, rarely branched, straight, parallel along the tubes, 2.5 – 4 μm diam. Setae frequent, distinctly subulate, arising from trama, most part embedded in hymenium, slightly curved at base, dark brown, thick-walled, 22 – 43 × 4 – 8 μm; cystidia and cystidioles absent; basidia more or less barrel-shaped, with four sterigmata and a simple septum at the base, 9 – 15 × 4 – 6 μm; basidioles in shape similar to basidia, distinctly smaller. Basidiospores oblongellipsoid to ellipsoid, hyaline, thin-walled, smooth, IKI–, CB–, (3.4–) 3.7 – 4.3 (−4.4) × (1.8–) 1.9 – 2.4 (−2.5) μm, L = 3.92 μm, W = 2.18 μm, Q = 1.8 (n = 30/1).

Material examined: CHINA, Zhejiang Province, Yongjia County, Longwantan Forest Park, on angiosperm stump, 21 August 2011, Cui 10163 (BJFC011058, holotype), (IFP019138, isotype).

Notes: Hymenochaete subporioides resembles H. porioides by its pore size (H. porioides: 7 – 9 permm, Ryvarden 2004; 6 –  8 per mm, measured from LWZ 20140719 – 11) and duplex context separated by two black lines, but microscopically H. subporioides could be easily differentiated by its larger basidiospores (H. porioides: 2.5 – 3.5 × 1.5 – 2 μm, Ryvarden 2004; 2.5 –3.1 × 1.5 – 1.9 μm, measured from LWZ 20140719 – 11). The ITS-based phylogeny (Fig. 1) also supports H. subporioides was separated from H. porioides.

Fig. 1 Phylogenetic position of Hymenochaete micropora and H. subporioides (in bold-face) inferred from ITS sequences. Topology is from maximum likelihood analysis; statistical values from maximum likelihood and maximum parsimony (simultaneously above 50 %) for each node are indicated at the branches.

Fig. 2 Hymenochaete subporioides microscopic structures (BJFC011058, holotype) a Basidiospores b Basidia and basidioles c Hymenial setae d Hyphae in trama e Hyphae in lower context Scale bars: a = 5 μm, b – e = 10 μm.