In: Sydowia 79, (2027): 1-26; ISSN 0082-0598, DOI 10.12905/0380.sydowia79-2027-0001, Published online on July 2nd, 2026

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

1 Via Garibaldi 173, I-45010 Villadose (RO) Italy; https://orcid.org/0000-0003-1922-1324
2 Viale G. Marconi 196, I-00146 Rome, Italy
3 Department of Agronomy, Food, Natural Resources, Animals and Environment (DAFNAE), University of Padova, Viale
dell’Università 16, I-35020 Legnaro (PD), Italy
4 Botanical Garden, University of Padova, Via Orto Botanico 15, I-35123 Padova, Italy
5 Department of Environmental Science, Policy, and Management (ESPM), University of California, 54 Mulford Hall,
Berkeley, CA, USA

* Corresponding author: pietrovoto@libero.it

Voto P., Migliozzi V., Forin N., Scali E. & Garbelotto M. (2026) 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. – Sydowia 79: 1–26.

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