LAUSR

A new genus of corticoid wood-inhabiting fungus, Callosus, typified by C. wenshanensis, is proposed here based on morphological and molecular characters. The species is characterized by resupinate basidiomata with smooth, cream-colored hymenial surfaces, a monomitic hyphal system with generative hyphae bearing simple septa, and basidiospores (2.3–3.9 × 1.4–2.3 μm) that are ellipsoid, hyaline, thin-walled, and smooth. The nrDNA internal transcribed spacer (ITS) and large subunit (28s) sequences were analyzed using maximum likelihood, maximum parsimony, and Bayesian inference methods. Phylogenetic analysis supported Callosus in a monophyletic lineage closely related to Phanerochaete and Rhizochaete.