Addition of four new wood-inhabiting fungi of Russulales (Agaricomycetes, Basidiomycota) from southwestern China

The species diversity of the families Peniophoraceae and Stereaceae (Russulales) in the high-altitude forests of southwestern China remains poorly explored. In this study, the detailed morphological characteristics and combined two-locus phylogenetic analyses based on the internal transcribed spacer (ITS) and large subunit (nLSU) regions of nuclear ribosomal DNA (rDNA) revealed four new wood-inhabiting species from southwestern China, belonging to the genera Baltazaria , Scytinostroma , Vararia , and Xylobolus . Their morphology and combined ITS + nLSU dataset showed that three of them grouped within Peniophoraceae , viz., Baltazaria yunnanensis , Scytinostroma sinense , and Vararia dehongensis , whereas Xylobolus yunnanensis clustered within Stereaceae . Descriptions, illustrations, and phylogenetic analysis results of the new taxa are provided. This study expands knowledge of Russulales diversity in China and provides baseline data for the conservation and sustainable utilization of fungal resources.