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.