Szczepkamyces quercicola Y.C. Dai, Yuan Yuan & Meng Zhou, sp. nov. (Figs. 2–3)

MycoBank no.—MB 846058

Etymology:— Quercicola (Lat.): refer to the species growth on Quercus apuifolloides .

Type:— CHINA. Yunnan Province, Deqin County, Meili Snow Mts. Geopark, Mingyong, on dead branch of living tree of Quercus apuifolloides, elev. 3200 m, N 28°27′23″, E 98°45′5″, 4.IX.2021, Dai 22812 (Holotype! BJFC037385) .

Fruiting body:—Basidiocarps annual, resupinate, corky, without odor or taste when fresh, becoming hard corky to rigid upon drying, up to 8 cm long, 4 cm wide, and 4 mm thick at center; sterile margin distinct in juvenile, cream, up to 2 mm wide, almost lacking when mature. Pore surface orange yellow to curry yellow when fresh, yellowish brown when dry; pores round to angular, 1–3 per mm; dissepiments thick, entire; subiculum cream, corky, up to 1 mm thick; tubes cream to buff yellow, hard corky to rigid, up to 3 mm long.

Hyphal structure:—Hyphal system dimitic; generative hyphae with clamp connections; skeletal hyphae IKI–, CB–; tissues unchanged in KOH (not dissolved).

Subiculum. Subicular generative hyphae hyaline, thin-walled, occasionally branched, 2.5–3.5 µm in diam; skeletal hyphae dominant, thick-walled with a narrow lumen, frequently dichotomously branched, flexuous, interwoven, 2.5–3 µm in diam.

Tube:—Tramal generative hyphae hyaline, thin-walled, occasionally branched, 2.5–3 µm in diam; skeletal hyphae dominant, thick-walled with a narrow lumen, frequently branched, strongly gelatinous, flexuous, interwoven, 2–3.5 µm in diam. Dendrohyphidia present at dissepiment edge. Hyphal pegs absent. Cystidia and cystidioles absent. Basidia clavate to pear-shaped, with four sterigmata and a basal clamp connection, 37–54 × 9–13 µm; basidioles in shape similar to basidia, but smaller, usually with a few guttules. Tetrahedric or polyhedric crystals frequently present among tube trama and hymenium.

Spores:—Basidiospores cylindrical, hyaline, thin-walled, smooth, usually mono-guttulate, IKI–, CB–, (14.6–)15– 17.5(–18) × 5–6 µm, L = 16.34 µm, W = 5.52 µm, Q =2.81–3.10 (n = 60/2).

Additional specimens studied:— CHINA. Yunnan Province, Deqin County, Meili Snow Mts. Geopark, Mingyong, on dead branch of living tree of Quercus apuifolloides, elev. 3200 m, N 28°27′23″, E 98°45′5″, 4.IX.2021, Dai 22805 (BJFC037378) , Dai 22807 (BJFC037380) , Dai 22810 (BJFC037383) .