Systematic study of Panaeolus (Agaricales, Galeropsidaceae) sensu lato and psilocybin-producing traits of species from China

Panaeolus sensu lato is a group of hallucinogenic mushrooms commonly found on dung, in pasture areas, grasslands, and forests. Previous studies indicated that the Panaeolus s.l. clade (panaeo-clade) could be ranked as a family ( Galeropsidaceae ), pending further evidence. In this study, based on phylogenomic, multigene phylogenetic, molecular clock, and morphological analyses, the panaeo-clade is demonstrated to be a distinct family, separate from Bolbitiaceae. The taxonomic system of Galeropsidaceae is revised. The genera accepted in Galeropsidaceae are Panaeolus and Staktophyllus, whereas Crucispora and Panaeolopsis are synonymized under Panaeolus. Three subgenera are accepted in Panaeolus: subg. Bresadolomyces, subg. Panaeolina, and subg. Panaeolus. Subgenus Bresadolomyces is roughly equivalent to the traditional circumscription of subg. Copelandia but is extended to include species formerly placed in Crucispora. Subgenus Panaeolina comprises most species from China and Anellaria-like species. Subgenus Panaeolus mainly comprises the P. papilionaceus species complex and a western Asian clade represented by P. punjabensis. In this study, one new subgenus and eight new species are proposed. Species from China are documented with descriptions, photographs, and illustrations. Additionally, the psilocybin-producing traits of 14 species were tested using high-performance liquid chromatography-tandem mass spectrometry (HPLC-MS). Two species are confirmed to possess psilocybin-producing traits, namely the known species P. cinctulus and the new species P. subfoenisecii proposed in this study. The evolution of the coprophilous lifestyle and psilocybin-producing traits in Panaeolus is also discussed based on phylogenetic relationships and divergence times.