Phylogenetic and taxonomic re-assessment of the genera <i>Echinoderma</i> and <i>Lepiota</i>

The infrageneric classification of the genus <i>Lepiota</i> has a long history of continuous refinement. Nevertheless, recent studies demonstrated that some of the widely used sections are not monophyletic in their current circumscription. In addition, the genus <i>Echinoderma</i>, or <i>L.</i> sect. <i>Echinatae</i> in the traditional sense, was shown to be polyphyletic. In this work, the phylogeny and taxonomy of the sections of <i>Lepiota</i> and the species attributed to <i>Echinoderma</i>/sect. <i>Echinatae</i> are analysed based on morphological investigation and a multilocus phylogeny (ITS, LSU, mtSSU, <i>RPB2</i>). Barcode ITS-sequences are provided for 11 type specimens for the first time. The genus <i>Echinoderma</i> is confirmed as a phylogenetically distinct clade. However, species so far treated in <i>Echinoderma</i>/sect. <i>Echinatae</i> form two further clades in <i>Lepiota</i>, one as basal clade in sect. <i>Lepiota</i> and the other as a section on its own, for which the new combination <i>L.</i> sect. <i>Eriophorae</i> is introduced. <i>Lepiota</i> sect. <i>Stenosporae</i> is validated as a result of a nomenclatural re-assessment. Lectotypes and epitypes are designated for <i>Lepiota carinii</i> and <i>Echinoderma perplexum</i>. <i>Echinoderma asperum</i> as currently circumscribed is shown to be a complex formed by at least four distinct clades. The re-assessment and emendation of the sections in <i>Lepiota</i> confirm that the microstructure of the pileus covering is the taxonomically most significant character, while the shape of the basidiospores is less uniform within the sections. <b>Citation:</b> Sarawi S, Piepenbring M, Reschke K (2025). Phylogenetic and taxonomic re-assessment of the genera <i>Echinoderma</i> and <i>Lepiota</i>. <i>Fungal Systematics and Evolution</i> <b>15</b>: 235-263. doi: 10.3114/fuse.2025.15.11.