Teratosphaeria Syd. & P. Syd., Annls mycol. 10(1): 39 (1912)
Index Fungorum number: IF 5377; Facesoffungi number: FoF 01713, 36 morphological species (Species Fungorum 2021), several species with molecular data.
Pathogenic on leaves. Sexual morph: Stromata comprising of brown, septate hyphae, superficial or immersed in host tissue, sometimes grouped together. Ascomata scattered, immersed in densely branched fibrils, arranged under a brown, flattened, root-like stroma in the leaf surface, subglobose to globose, black, uniloculate, thick-walled, with well-developed ostiolar periphyses, slightly pseudoparaphysoidal in immature ascomata. Peridium thick-walled, comprising 2–3 brown cell layers of textura angularis; inner cells of flattened, hyaline cells. Hamathecium when present consisting of sub cylindrical, branched, septate pseudoparaphyses, or reduced to hyaline periphysoids lining the ostiole. Asci 8-spored, bitunicate with endotunica, sessile or short pedicellate, clavate, apex rounded or tapered, with ocular chamber. Ascospores overlapping, fusiform to cylindrical, 1-septate, slightly constricted at the septum or not, often curved, rounded on both sides and upper cell slightly obtuse, rough and thick-walled, hyaline to brown. Asexual morph: Hyphae dark brown, septate, branched, mostly immersed. Conidiomata acervular to sporodochial, well-developed or reduced, solitary, brown, with pseudoparenchymatal wall. Conidiogenous cells integrated, terminal or reduced to conidiogenous cells, proliferating per currently and sympodially. Conidia verrucose, thin to thick-walled, brown, with dehiscence scars on conidial body (Adapted from Crous et al. 2009b).
Type species: Teratosphaeria fibrillosa Syd. & P. Syd.
Notes: Teratosphaeria was introduced by Sydow and Sydow (1912) with T. fibrillosa as the type species. Teratosphaeria is compared with Mycosphaerella based on its asci with multi-layered endotunica, ascospores that darken in mature asci and often upon germination. Taylor et al. (2003) synonymized Teratosphaeria with Mycosphaerella based on sequence data. Crous et al. (2007) showed that Mycosphaerella was polyphyletic and separate complex taxa into different families and genera.