Phylogenetic and Phylogenomic Analyses Reveal New Taxa in Clitocybaceae, with Notes on Poisonous Species and Spore Evolution.

Clitocybaceae is a family of predominantly saprotrophic fungi with important edible and medicinal value. However, the edibility and toxicity of many species within this family remain unknown, posing a poisoning risk. In this study, 24 Chinese specimens, most of which were collected from poisoning sites, were identified. Phylogenetic analyses based on ITS and six loci (ITS, LSU, TEF1, RPB1, RPB2, and ATP6) and a phylogenomic analysis based on 485 single-copy genes were conducted to determine their placement within Clitocybaceae. Their morphological features were observed, particularly the spore surface. Based on the obtained results, a new genus with distinctly verrucose spores, Allolepista, is proposed to accommodate the clade that exhibits a very large genetic distance from its sister clade, Lepista s.str. A new species, Clitocybe sinensis, is described. Three new combinations, A. crenata (≡L. crenata), A. benekei (≡Cli. benekei), and A. rhodotoides (≡L. rhodotoides), are made. Clitocybe violaceifolia, originally described from the Pacific coast of the USA, is reported for the first time in China. Collybia sinoborealis and Pseudolyophyllum liwanense are found to be junior synonyms of Col. violea and A. benekei, respectively, while Cli. lamoureae and Col. urbana turn out to be synonymous with Cli. truncicola. Based on the symptoms observed in poisoning cases, A. benekei is found to cause gastroenteritis, while Cli. sinensis, Cli. truncicola, Col. bisterigmata, Col. brunneoumbilicata, and Col. subtropica lead to muscarinic syndrome. These results expand our understanding of the toxicity and species diversity of Clitocybaceae, providing a reference for public food safety.