Three new wood-inhabiting corticioid fungi from the Qinling Mountains, China

Wood-inhabiting fungi are key decomposers in forest ecosystems, but the diversity of corticioid fungi in the Qinling Mountains remains insufficiently explored. During surveys of macrofungi in Zhashui County and Shangzhou District in the Qinling Mountains, several specimens representing three undescribed taxa of corticioid fungi were collected. Based on detailed morphological examinations and phylogenetic analyses of combined ITS + nLSU datasets by using Maximum Likelihood and Bayesian Inference methods, three new species, viz.

Hymenochaete zhashuiensis, Hyphoderma brevicystidiatum and Steccherinum shangzhouense, are described and illustrated. Hymenochaete zhashuiensis is characterized by effused-reflexed basidiomata with a reddish to rust-brown, cracked hymenial surface, abundant dark brown hymenial setae, the presence of dendrohyphidia, and ellipsoid to broadly ellipsoid basidiospores (4–5.6 × 2.8–3.5 µm). Hyphoderma brevicystidiatum is distinguished by resupinate, basidiomata white to cream with hymenial surface, clamped generative hyphae, short cylindrical to subcylindrical cystidia, subclavate to clavate basidia, and ellipsoid to subcylindrical basidiospores (6.2–10 × 2.7–4.2 µm).

Steccherinum shangzhouense is characterized by resupinate and membranaceous basidiomata, a white to cream, tuberculate to slightly grandinioid and cracked hymenial surface, simple-septate generative hyphae, the absence of cystidia and skeletocystidia, and broadly ellipsoid to oblong ellipsoid basidiospores (5.2–7.9 × 2.5–5 µm). These findings enrich the wood-inhabiting fungal diversity in the Qinling Mountains and indicate that this region remains underexplored for wood-inhabiting fungi.