Metathyriella Syd., Annls mycol. 25(1/2): 96 (1927).
MycoBank number: MB 3146; Index Fungorum number: IF 3146; Facesoffungi number: FoF 07047; 3 morphological species (Species Fungorum 2020), molecular data unavailable.
Type species – Metathyriella roupalae Syd., Annls mycol. 25(1/2): 96 (1927).
Notes – Metathyriella was introduced to accommodate an epiphytic fungus occurring on leaves of Roupala veraguensis (Proteaceae). The genus was originally described as thyriothecial, dimidiate-scutate, or orbicular ascomata, with irregular loose margin and indistinct basal membrane, the membrane covered by flattened, soft convex layer, irregularly lumpy at maturity, yellowish-brown to olive-brown, later more or less intense, periphery in a subhyaline membrane matrix, anastomosed paraphyses. Asci are 8-spored, bitunicate, ellipsoidal, or broadly ovoid to subglobose asci and ascospores are amalgamated, oblong-clavate, and 2-septate (Sydow 1927, Phookamsak et al. 2016). Sydow (1927) accommodated Metathyriella in Hemisphaeriaceae, however, von Arx & Müller (1975) placed it in Schizothyriaceae. Metathyriella is a poorly known genus, there are only three species and there is no molecular data to clarify its phylogenetic affinities. The type specimen of M. roupalae could not be located. Hence, Phookamsak et al. (2016) treated Metathyriella as a doubtful genus. However, Wijayawardene et al. (2018) placed the genus in Schizothyriaceae until the genus is clarified based on molecular data.