Cystinarius : phylogeny and species diversity in China

Cystinarius is a small genus belonging to the family Cortinariaceae, distinguished by its distinctive combination of small basidiospores and presence of both cheilo- and pleurocystidia, a combination that is rarely found in other genera within the Cortinariaceae. To date, this genus consists of only two subgenera and includes seven recognized species. Previously, only a single specimen of Cy. crassus was reported from China. Based on the analysis of 17 newly collected specimens, supported by morphological evidence and two-locus phylogenetic inference, five species, namely, Cy. fulvellus, Cy. longipes, Cy. shennongensis, Cy. crassus, and Cy. paurigarhwalensis, were recognized. Among them, the former three species are new to science, whereas the last one is new to China. This study provides comprehensive taxonomic descriptions and a detailed identification key to the Cystinarius species discovered in China.