The Combination of Morphological and Phylogenetic Evidence Reveals Four New Gymnopus Species and New Distribution

The genus <i>Gymnopus</i> plays a significant role in ecological systems, with certain species holding potential as food or medicinal resources. However, the species diversity of <i>Gymnopus</i> in China remains unclear. In recent years, more than one thousand <i>Gymnopus</i> specimens have been collected across China. Thus, through the integration of ecological evidence, detailed morphological studies, and phylogenetic analysis using a multiloci dataset of ITS + nLSU + <i>tef1-ɑ</i>, four new species-<i>Gymnopus longistipes</i>, <i>Gymnopus striatipileatus</i>, <i>Gymnopus viridiscus</i>, and <i>Gymnopus spadiceus</i>-have been differentiated from known species. <i>Gymnopus similis</i> has been newly documented from Jiangxi Province, China. Detailed descriptions and vivid illustrations have been provided based on the newly collected specimens, along with comparisons to closely related species. Additionally, a key to the reported species of <i>Gymnopus</i> s.l. from East China has been included.