Phylogenetic and taxonomic re-assessment of the genera Echinoderma and Lepiota.

Abstract

The infrageneric classification of the genus Lepiota 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 Echinoderma, or L. sect. Echinatae in the traditional sense, was shown to be polyphyletic. In this work, the phylogeny and taxonomy of the sections of Lepiota and the species attributed to Echinoderma/sect. Echinatae are analysed based on morphological investigation and a multilocus phylogeny (ITS, LSU, mtSSU, RPB2). Barcode ITS-sequences are provided for 11 type specimens for the first time. The genus Echinoderma is confirmed as a phylogenetically distinct clade. However, species so far treated in Echinoderma/sect. Echinatae form two further clades in Lepiota, one as basal clade in sect. Lepiota and the other as a section on its own, for which the new combination L. sect. Eriophorae is introduced. Lepiota sect. Stenosporae is validated as a result of a nomenclatural re-assessment. Lectotypes and epitypes are designated for Lepiota carinii and Echinoderma perplexum. Echinoderma asperum 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 Lepiota 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. Citation: Sarawi S, Piepenbring M, Reschke K (2025). Phylogenetic and taxonomic re-assessment of the genera Echinoderma and Lepiota. Fungal Systematics and Evolution 15: 235-263. doi: 10.3114/fuse.2025.15.11.