The genus <i>Thaxterogaster</i> (Cortinariaceae): phylogeny and species diversity in Western China

<i>Thaxterogaster</i> is the second largest genus within the family Cortinariaceae, comprising nearly two hundred species worldwide. However, the diversity of the genus in China remains largely unknown. Based on morphological evidence and phylogenetic inference of a five-locus dataset, one hundred twelve species belonging to seven subgenera and 23 sections of <i>Thaxterogaster</i> were analysed. We here describe 15 of those present in China, including 8 species new to science, namely <i>T. crassimultiformis</i>, <i>T. lavendulaceus</i>, <i>T. flavocapitatus</i>, <i>T. pallidopurpurascens</i>, <i>T. atricapitatus</i>, <i>T. cupreus</i>, <i>T. sordidus</i>, <i>T. alboparvus</i>, and 1 species new to China, viz. <i>T. indopurpurascens</i>. Two new combinations, <i>Thaxterogaster</i> subgenus <i>Vibratiles</i> and <i>Thaxterogaster tenuipes</i>, are further introduced. Taxonomic descriptions and a key to the species of <i>Thaxterogaster</i> in Western China are provided.