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

Panaeolus is a genus of small, dark-spored agarics within the family Galeropsidaceae Singer. 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, P. latifolius, P. praecox, and P. ovinus; and one new record for China: P. 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 of the genus Crucispora to a subgenus within Panaeolus, accommodating P. rhombispermus.