Two new corticioid species in Amylocorticiales and Atheliales (Agaricomycetes, Basidiomycota) from Southwestern China

Amylocorticiales and Atheliales (Basidiomycota) comprise corticioid, athelioid, and poroid fungi, characterized by smooth to pellicular hymenophores, a monomitic hyphal system, and smooth basidiospores. In this study, two new species from southwestern China, namely Leptosporomyces caeruleogriseum and Pseudoathelia fabri , are described and illustrated based on morphology characteristics and phylogenetic analyses of ITS and nLSU sequences. Leptosporomyces caeruleogriseum is characterized by coriaceous basidiomata with a bluish gray hymenophore surface when fresh, becoming soft membranous and cream to curry yellow upon drying, as well as by encrusted generative hyphae, and basidiospores are oblong ellipsoid, measuring 3–4 × 1.5–2 µm, and the species is currently known from Guizhou and Xizang, China. Pseudoathelia fabri is distinguished by a merulioid to tuberculate hymenophore with a white surface when fresh, a fimbriate sterile margin, and oblong ellipsoid basidiospores measuring 4.1–5.5 × 1.8–2.4 µm. To date, it is currently known only from Xizang, China. Phylogenetically, the new species Leptosporomyces caeruleogriseum was closely related to L. galzinii , the type species of Leptosporomyces , and forming independent clade in Atheliales, and Pseudoathelia fabri formed an independent lineage within the Pseudoathelia clade in Amylocorticiales.