Nigroporus subvinosus Y. C. Dai, X. L. Li & Yuan Yuan sp. nov.

Figs 7, 8

Holotype.

China • Xizang Autonomous Region, Linzhi, Motuo County, on rotten angiosperm wood, 24 October 2023, Dai 26787 (BJFC 044337).

Etymology.

Subvinosus (Lat.): refers to the species resembling Nigroporus vinosus.

Description.

Basidiomata. Annual, pileate, usually solitary, leathery and without odor or taste when fresh, becoming woody hard and light in weight upon drying; pilei semicircular to flabelliform, projecting up to 3.9 cm, 3.7 cm wide and 3 mm thick at base. Pileal surface dark grayish blue, vinaceous gray to black when fresh, become umber to fawn upon drying, concentrically zonate, glabrous, margin thin, cream. Pore surface flesh pink to brownish vinaceous when fresh, becoming fawn when bruised, reddish brown when dry; sterile margin distinct, white when dry, up to 2.3 mm wide; pores round to angular, 9–11 per mm; dissepiments thin, entire to lacerate. Context fawn to reddish brown, corky when dry, up to 1.7 mm thick. Tubes concolorous with pore surface, corky when dry, up to 1.3 mm long.

Hyphal structure. Hyphal system dimitic; generative hyphae bearing clamp connections; skeletal hyphae IKI –, CB –; tissues darkening in KOH.

Context. Generative hyphae hyaline, thin- to slightly thick-walled, occasionally branched, 3–4.4 µm in diam.; skeletal hyphae dominant, yellowish brown, thick-walled with a narrow lumen to subsolid, unbranched, slightly flexuous, interwoven, 3.3–4.5 µm in diam.

Tubes. Generative hyphae hyaline, thin- to slightly thick-walled, occasionally branched, 2.6–4.4 µm in diam.; skeletal hyphae dominant, yellowish brown, thick-walled with a narrow lumen to subsolid, unbranched, slightly flexuous, interwoven, 2.4–5 µm in diam. Cystidia absent; cystidioles frequent, fusoid, hyaline, thin-walled, smooth, 10–18 × 3–5 µm. Basidia barrel-shaped, with four sterigmata and a basal clamp connection, 6–10 × 3–4 µm. Basidioles of similar shape to basidia, but smaller.

Spores. Basidiospores allantoid, hyaline, thin-walled, smooth, usually with one or two guttules, IKI –, CB –, (2.9 –) 3–4.5 (– 5) × (1.4 –) 1.5–2.1 (– 2.3) µm, L = 3.7 µm, W = 1.78 µm, Q = 2.04–2.09 (n = 240 / 8).

Additional specimens examined

(paratypes). China • Guangxi Zhuang Autonomous Region, Shangsi County, Natura Subsidium magnum montem National, on dead angiosperm tree, 26 May 2024, Dai 27441 (BJFC 047701) . • Hainan Province, Baisha Li Autonomous County, Qingsong, on rotten wood of Pinus latteri, 10 June 2023, Dai 25154 (BJFC 042706) . • Sichuan Province, Yanyuan County, on stump of Pinus yunnanensis, 15 August 2019, Cui 17526 (BJFC 034385) . • Yunnan Province, Baoshan City, Gaoligongshan Nature Reserve, on angiosperm stump, 7 November 2019, Cui 18097 (BJFC 034956), Cui 18104 (BJFC 034963) . • Puer, Puer Forest Park, Xiniuping Scenic Spot, on rotten angiosperm wood, 17 August 2019, Dai 20445 (BJFC 032113) . • Yingjiang County, Tongbiguan Nature Reserve, on angiosperm stump, 30 October 2012, Dai 13136 (BJFC 013353) .