Marasasiomyces Crous, in Crous, Müller, Sánchez, Giordano, Bianchinotti, Anderson & Groenewald, Phytotaxa 202(2): 86 (2015).
Saprobic on the host plant. Sexual morph: Undetermined. Asexual morph: Conidiomata dark brown to black, semi-immersed, subglobose to pyriform, unilocular, setose, ostiolate. Ostiole subcylindrical, with an elongated neck covered by setae, centrally located. Setae brown to dark brown, septate, branched. Conidiomatal wall composed of thick-walled, brown to hyaline cells of textura angularis. Conidiophores reduced to conidiogenous cells. Conidiogenous cells holoblastic, cylindrical, determinate, formed from the inner layer of pycnidium. Conidia hyaline, subcylindrical to fusiform, aseptate, smooth-walled, bearing a cone-like, mucoid appendage at apex (Adapted from Crous et al., 2015).
Type species: Marasasiomyces karoo (B. Sutton & Marasas) Crous
Notes: Marasasiomyces was introduced by Crous et al. (2015) based on morphology and multigene analysis to accommodate the type species M. karoo. Marasasiomyces was differs from Tiarosporella by conidiomata with long necks shielded in brown setae, and holoblastic conidiogenesis. Marasasiomyces is morphologically and phylogenetically a distinct and well-defined genus in Botryosphaeriaceae.