In: Sydowia 78, (2026): 259-281; ISSN 0082-0598, DOI 10.12905/0380.sydowia78-2026-0259, Published online on january 12th, 2026

Octospora gamundiana, sp. nov., (Pezizales) from Argentina, a bryophilous ascomycete on the moss Syntrichia fragilis (Pottiaceae)

Guillermo M. Suárez, Facundo G. Dominguez, Hipólito Pajot, Jan Eckstein, Lukáš Janošík, Jorge R. Flores & Myriam del Valle Catania

Facultad de Ciencias Naturales e I.M.L., Universidad Nacional de Tucumán, Miguel Lillo 205, (T4000JFE) San Miguel de Tucumán, Tucumán, Argentina
Unidad Ejecutora Lillo (CONICET – Fundación Miguel Lillo), Miguel Lillo 251 (T4000JFE) San Miguel de Tucumán, Tucumán, Argentina
PROIMI – CCT. Avenida Belgrano y Pasaje Caseros (T4000JFE) San Miguel de Tucumán – Tucumán, Argentina
Arnoldiweg 20, 37083 Göttingen, Germany
Department of Botany, Faculty of Science, Charles University, Benátská 2, CZ-12800 Prague, Czech Republic
Institute of Botany of the Czech Academy of Sciences, Zámek 1, CZ-25243 Pruhonice, Czech Republic
Instituto Criptogámico, Sección Micología, Fundación Miguel Lillo. Miguel Lillo 251 (T4000JFE) San Miguel de Tucumán, Tucumán, Argentina

* e-mail: suarezgm@csnat.unt.edu.ar

Suárez G.M., Dominguez F.G., Pajot H., Eckstein J., Janošík L., Flores J.R. & Catania M.V. (2026) Octospora gamundiana, sp. nov. (Pezizales) from Argentina, a bryophilous ascomycete on the moss Syntrichia fragilis (Pottiaceae). – Sydowia 78: 259–281.

Octospora gamundiana is described and illustrated based on Argentinean collections. It is the first species of bryophilous Pezizales known to infect the acrocarpous moss Syntrichia fragilis (Pottiaceae). The new species has a distinctive combination of morphological traits and is also supported by multilocus phylogenetic analyses. Octospora gamundiana is characterized by ellipsoid ascospores with a slightly uneven surface and by its specific host association. A comparison with similar Octospora species is provided. This study increases our knowledge of the diversity of bryophilous Pezizales in South America.

Keywords: Ascomycota, new species, Pyronemataceae, Pezizomycotina, phylogeny, taxonomy. – 1 new species.