A comparative European-North American study of the mycophagous Psathyrella epimyces complex (Psathyrellaceae, Agaricales), with two new Psathyrella species and notes on the host fungi Coprinus ovatus and Coprinus comatus sensu lato

Pietro Voto, Vincenzo Migliozzi, Niccolò Forin, Edoardo Scali & Matteo Garbelotto

Sydowia 79: 1-26

Published online on July 2nd, 2026

Morphological, ecological, and molecular analyses of various Psathyrella epimyces collections suggest that this species may represent a species complex recognized as P. epimyces sensu lato. Phylogenetic analyses of two loci (ITS and tef1) identified three statistically supported subclades within P. epimyces sensu lato. Each subclade shows specialization on different fungal hosts. Psathyrella epimyces sensu stricto parasitizes Coprinus comatus and Coprinopsis atramentaria on eutrophic substrates; P. oligoepimyces sp.nov. parasitizes Coprinus ovatus on oligotrophic substrates and P. litoriepimyces sp. nov. is associated with Coprinus sp. in coastal sand dunes. We propose the new term plagiohymeniderm to describe the distinctive pileipellis structure observed in species of the Psathyrella epimyces complex. Phylogenetic analyses of the hosts confirm the distinction between Coprinus ovatus and C. comatus. Furthermore, the new species Coprinus sudamericanus, belonging to C. comatus group, is described and C. comatus var. caprimammillatus is elevated to species level.

Keywords: Basidiomycota, Basidiomycetes, Agaricineae, phylogeny, morphology, taxonomy, old types. – 3 new species, 1 new combination

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