Loosening the belt: unknown diversity of the strangled stinkhorn genus Staheliomyces (Phallales, Basidiomycota)

Known to date only from the Neotropics, the genus Staheliomyces E. Fisch. (Phallaceae, Phallales) was described from Suriname with only a single species, S. cinctus E. Fisch. Nearly 100 years have passed since the original description, and its systematic position and species diversity have not been investigated. Collections from Brazil and Costa Rica were studied, and four new species are described based on morphology, molecular phylogenetic analyses, and nomenclatural review. We provide morphological descriptions together with a key to species, and a proposal to emend the genus. We review the type material of S. cinctus located in herbarium of Botanischer Garten der Universitat Bern (BERN), and establish the phylogenetic position of the genus which clusters with Xylophallus (Schltdl.) E. Fisch. in an exclusively neotropical clade. Our results highlight the importance of studying neglected taxa that impacts knowledge of biodiversity especially for localities that have been poorly collected. The study of herbarium collections can reveal data on forgotten type materials and shed light on the work of pioneering mycologists. This study also brings insights into biogeographical diversity of the phalloid fungi.

Automated summary

In this study, the systematic position and species diversity of the genus Staheliomyces E. Fisch. were investigated based on collections from Brazil and Costa Rica. Four new species were described using morphological and molecular phylogenetic analyses, and the genus was proposed to be emended. The phylogenetic position of the genus was established, and it clusters with Xylophallus (Schltdl.) E. Fisch. in an exclusively neotropical clade.