Dimeriella Speg., Revta Mus. La Plata 15(2): 12 (1908).
Index Fungorum number: IF 1575; Facesoffungi number: FoF 06359, 25 morphological species (Species fungorum 2021), molecular data unavailable.
Saprobic on dead leaves. Sexual morph: Ascomata superficial, solitary, scattered, globose to subglobose, black, covered by hyaline mycelium, with sparse setae, olivaceous to dark brown, tapering towards the subacute apex, septate. Peridium 10–13 µm wide, comprising dark brown cells of textura angularis, inner layers reddish-brown, lacking pseudoparaphyses. Asci 8-spored, bitunicate, fissitunicate, ovoid-subclavate, sessile, apically thickened. Ascospores 2-seriate, 1 to 3-septate, constricted at the septum, hyaline, becoming brownish at maturity, smooth-walled. Asexual morph: Undetermined.
Type species: Dimeriella hirtula Speg.
Notes: Dimeriella was introduced by Spegazzini (1908) with D. hirtula as type species. Dimeriella is characterized by small, sub globose, darkly pigmented ascomata with sparse dark brown and short setae and absence of pseudoparaphyses. Dimeriella and its type species, D. Hirtula have been re-studied and compared with similar genera by several authors (Theissen and Sydow 1917; Toro 1939; Hansford 1946; Müller and von Arx 1962; Farr 1963, 1965). Farr (1979) excluded Dimeriella from Dimeriaceae based on the centrum structure of the type species, D. hirtula. Hyde et al. (2013), accepted Dimeriella in the family Perisporiopsidaceae (= Parodiellinaceae G. Arnaud) based on its habitat and characteristics. Boonmee et al. (2017) re-examined the type specimen D. hirtula and concluded that Dimeriella is similar to other genera in Venturiaceae based on the superficial, darkly pigmented, sparse, short setae, and 1 to 3-septate, hyaline to brown ascospores.