Seynesiopeltidaceae K.D. Hyde, in Hyde et al., Fungal Diversity 63: 232 (2013).

MycoBank number: MB 804042; Index Fungorum number: IF 804042; Facesoffungi number: FoF 06522, 1 species.

Foliar epiphytes on leaves, causing black spots, usually confluent in groups, forming black colonies. Sexual morph: Mycelium superficial, sparse, light, septate, olive-green. Thyriothecia solitary or gregarious, superficial, circular, shield-like, shallow, conical, dome-like, flattened, upper region, carbonaceous, unilocular, brown to black, basal layer poorly developed, lacking a distinct central ostiole. Upper wall comprising radiating arranged parallel cells, cells at margin branching. Hamathecium comprising 1–3 µm wide, comprising numerous, cellular, branched pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, saccate, with a knob- like pedicel, and conspicuous ocular chamber (in Congo red). Ascospores irregularly 2–3-seriate, dark brown when mature, 1-septate, strongly constricted at septum, upper cells longer and wider, basal cell shorter and narrower with an acute base, with a thick, structured, hyaline, cell wall. Asexual morph: Undetermined.

Type: Seynesiopeltis F. Stevens & R.W. Ryan.

Notes: Seynesiopeltidaceae was introduced by Hyde et al. (2013) based on the unique brown ascospores with thick structured walls and thick ascus wall when stained in Congo red. The cells of the peridium consist of two strata of textura angularis cells. Ascomata are described as thyriothecia-like and they resemble some genera in Parmulariaceae (e.g. Polycyclus andinus, Inácio and Cannon 2008). Genera such as Dothidasteroma and Cocconia (also Parmulariaceae) may also be related as they have brown ascospores, but the asci are significantly different (Inácio and Cannon 2008). Notably, Seynesiopeltis differs from Parmularia, the type genus of Parmulariaceae. In Parmularia styracis, the thyriothecia have a similar appearance to shells on the host surface, the asci are obclavate and ascospores are hyaline.