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

<i>Panaeolus</i> 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 <i>Panaeolus</i> and identified 17 species. These include four new species: <i>Panaeolus bambusicola</i>, <i>Panaeolus latifolius</i>, <i>Panaeolus praecox</i>, and <i>Panaeolus ovinus</i>; and one new record for China: <i>Panaeolus fraxinophilus</i>. 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 <i>Crucispora</i> to a subgenus within <i>Panaeolus</i>, accommodating <i>P. rhombispermus</i>.