Roussoellopsis I. Hino & Katum., J. Jap. Bot. 40: 86 (1965).

MycoBank number: MB 4800; Index Fungorum number: IF 4800; Facesoffungi number: FoF 01778; 3 morphological species (Species Fungorum 2020), 2 species with molecular data.

Type speciesRoussoellopsis japonica (I. Hino & Katum.) I. Hino & Katum., J. Jap. Bot. 40: 86 (1965).

Didymosphaeria japonica I. Hino & Katum., Bull. Faculty of Agriculture, Yamaguchi University 5: 229 (1954).

Notes – Phookamsak et al. (2014b) designated the epitype specimen and obtained the molecular data for Roussoellopsis macrospora. Meanwhile, Liu et al. (2014) accepted the genus in Roussoellaceae based on molecular phylogeny of representative species, R. macrospora and R. tosaensis. Roussoellopsis often forms a distinct clade, close to Roussoella sensu lato (Liu et al. 2014, Phookamsak et al. 2014b, 2019, Dai et al. 2017, Jiang et al. 2019, Karunarathna et al. 2019). However, the genus can be distinguished from Roussoella in having cylindric-clavate to clavate asci, with trabeculate pseudoparaphyses, pale yellowish to dark brown, fusiform, with acute ends 1- septate, rough-walled with echinulate, or longitudinal striations ascospores and forming melanconiopsis-like or neomelanconium-like asexual morph (Liu et al. 2014, Phookamsak et al. 2014b). More taxon sampling and molecular data for the type species are required for a better understanding of the natural placement of this genus.