Ruptoseptoria Quaedvl., Verkley & Crous, Stud. Mycol. 75: 356 (2013).
Index Fungorum number: IF 804428; Facesoffungi number: FoF 08561, 1 morphological species (Species Fungorum 2021), 1 species with molecular data.
Foliicolous, plant pathogenic. Sexual morph: Unknown. Asexual morph: Conidiomata black, appressed, elongated, pycnidial, but opening via irregular rupture, convulated; exuding a creamy white conidial mass; outer wall dark brown, crusty, consisting of 6–8 layers of dark brown textura angularis; giving rise to 2–3 inner layers of pale brown to hyaline textura angularis. Conidiophores lining the inner cavity, hyaline, smooth or pale brown, verruculose at base, branched below, septate, subcylindrical. Conidiogenous cells integrated, terminal, subcylindrical, smooth; proliferating sympodially at apex, or apex phialidic with minute periclinal thickening. Conidia solitary, hyaline, smooth, guttulate, subcylindrical to narrowly obclavate, gently to irregularly curved, apex subobtuse, base truncate to narrowly obovoid, transversely septate (adapted from Quaedvlieg et al. 2013).
Type species: Ruptoseptoria unedonis (Roberge ex Desm.) Quaedvl., Verkley & Crous
Notes: Ruptoseptoria resembles Septoria but differs in having convulated conidiomata that open by irregular rupture and conidiogenous cells that are often phialidic. Ruptoseptoria is a distinct genus in Mycosphaerellaceae and can be identified based on DNA sequence data. Molecular markers available for Ruptoseptoria are ITS, LSU, BTUB and RPB2.