Studies in Lepiota (Agaricales, Verrucosporaceae): supporting the merger of Chamaemyces into Lepiota and proposing two new species

The taxonomic status of Chamaemyces as a genus separate from Lepiota has recently been questioned, as its type species has been transferred to Lepiota, implicitly rendering the merger of Chamaemyces as a synonym without a resolved sectional assignment or morphological validation. Multilocus (ITS, LSU, rpb 2, mtSSU) phylogenetic analyses robustly place this transferred species within L. sect. Cristatae, and detailed morphological re-evaluation further supports the merger.

The recently proposed seven-section classification of Lepiota is largely supported by the phylogenetic framework, which also clarifies the phylogenetic position of L. angusticystidiata. Furthermore, two novel species are described and illustrated: L. pallidovelata (sect. Lepiota), which is characterized by whitish squamules on the pileus with veil remnants, and L. stillispora (sect.

Helveolae), distinguished by its droplet-shaped basidiospores. Both the sectional assignment and the proposal of novel species were further independently confirmed by a comprehensive ITS phylogeny of the genus. This study provides conclusive phylogenetic and morphological evidence for the prior merger and expands the known diversity of Lepiota in East Asia with two new taxa.