Rosisphaerella Videira & Crous, in Videira et al., Stud. Mycol. 87: 350 (2017).
Index Fungorum number: IF 822703; Facesoffungi number: FoF 08560, 1 morphological species (Species Fungorum 2022), 1 species with molecular data
Pathogenic, foliicolous. Sexual morph: Unknown. Asexual morph: Mycelium internal, composed of sub hyaline to brown hyphae, smooth, septate, branching. Stromata lacking or small, epidermal, sub stomatal, brown to dark brown. Conidiophores emerging from stromata or few brown cells, solitary to fasciculate, often synnematous, dark olivaceous brown near base and paler toward the tip, smooth, simple, multiseptate, straight to sinuous, usually geniculate-sinuous. Conidiogenous cells integrated, terminal and intercalary, proliferating sympodially, rarely proliferating percurrently, with rim-like conidiogenous loci, somewhat thickened, darkened and protuberant. Conidia solitary, pale to medium olivaceous brown, smooth to finely verruculose, cylindrical to obclavate, straight to mildly curved, septate, obconically truncate at base and rounded at apex, hila somewhat thickened and darkened (adapted from Videira et al. 2017).
Type species: Rosisphaerella rosicola (Pass.) U. Braun, C. Nakash., Videira & Crous
Notes: Rosisphaerella rosicola was previously known as Passalora rosicola which cause leaf spot disease on rose worldwide (Davis 1938). Rosisphaerella is phylogenetically closely related to Phaeocercospora and Pleopassalora. Rosisphaerella differs from these genera in lacking pleomorphic asexual morph and percurrent conidiation. Molecular markers available for Rosisphaerella include ITS, LSU and RPB2.