Alloexidiopsis crystallina , a New Species From Yunnan, Southwest China, Based on Morphology and Phylogeny

Alloexidiopsis is a small genus of wood‐inhabiting basidiomycetes, currently comprising only eight described species. Recent study has clarified the classification of this genus by combing phylogenetic analyses and morphological characteristics. However, the species diversity of Alloexidiopsis in the high‐altitude forests of Yunnan Province, China, has not been systematically studied. In the present study, detailed morphological characteristics and combined multilocus phylogenetic analyses based on the internal transcribed spacers (ITS) and the large subunit (nrLSU) of the nuclear ribosomal DNA (rDNA) revealed that this new species grouped into Alloexidiopsis , viz., A. crystallina . This species is characterized by hard membranaceous basidiomata with a grandinioid hymenial surface, a monomitic hyphal system, and allantoid basidiospores measuring 11.5–16 × 5–6.5 µm. The new species forms a distinct lineage within Alloexidiopsis and is closely related to A. grandinea and A. nivea . Its subclavate cystidia with obtuse apices distinguish it from A. grandinea , which has fusiform cystidia with acute apices. The grandinioid hymenial surface further separates it from A. nivea , which has a smooth hymenial surface. Comprehensive descriptions, micrographs, and phylogenetic analyses results are provided. The present study enriches the species diversity of Auriculariales in China that should benefit to protect and sustainably use the natural resources of fungi.