Morphological and molecular identification of <italic>Asterostroma roseoalbum</italic> sp. nov. (Peniophoraceae, Russulales), from southwestern China.

<italic>Asterostroma roseoalbum</italic> sp. nov. was found in Yunnan Province, China, is described here as a new species based on its morphology and phylogeny. <italic>Asterostroma roseoalbum</italic> is characterised by its felted-membranous to pellicular, fimbriate basidiomata with a smooth hymenophore and a dimitic hyphal system bearing generative hyphae with simple-septate and echinulate, subglobose to globose basidiospores measuring as 8–9.5 × 7–9 µm. Phylogenetic analyses of the new species were based on the internal transcribed spacer (ITS) and large subunit (nrLSU) of ribosomal DNA (rDNA) sequences. The phylogenetic analysis indicated that the new species belongs to the genus <italic>Asterostroma</italic>, and is closely related to two species <italic>A. macrosporum</italic> and <italic>A. muscicola</italic>. A full description, illustrations and phylogenetic analysis results of the new species are provided. Furthermore, a key to the genus <italic>Asterostroma</italic> in China is provided. [ABSTRACT FROM AUTHOR]