Four New Species and a New Record of Panaeolus from China, with Notes on the Taxonomy of Panaeolus rhombispermus

Panaeolus is a genus of small, dark-sporeda agarics within the family Galeropsidaceae. Based on the majority of specimens collected from China, this study investigated the genus Panaeolus and identified 17 species. These include four new species: Panaeolus bambusicola, Panaeolus latifolius, Panaeolus praecox, and Panaeolus ovinus; and one new record for China: Panaeolus fraxinophilus. The new species and the newly recorded species for China are morphologically described and illustrated. A multi-locus phylogenetic analysis (ITS, nrLSU, tef1-α, rpb2) was conducted using maximum likelihood and Bayesian inference. Combined morphological and phylogenetic evidence supports the reduction in the genus Crucispora to a subgenus within Panaeolus, accommodating P. rhombispermus.