Platystomum Trevis., Bull. Soc. R. Bot. Belg. 16: 16 (1877).
MycoBank number: MB 4185; Index Fungorum number: IF 4185; Facesoffungi number: FoF 00814; 40 morphological species (Species Fungorum 2020), 4 species with molecular data.
Type species – Platystomum compressum (Pers.) Trevis., Bull. Soc. R. Bot. Belg. 16: 16 (1877).
≡ Sphaeria compressa Pers., Syn. meth. fung. (Göttingen) 1: 56 (1801).
Notes – The type species of this genus, Platystomum compressum was originally described as Sphaeria compressa by Cesati & De Notaris (1863). The species can be saprobes (Kirk et al. 2008). Previously this genus was treated as Pleosporales, genera incertae sedis (Lumbsch & Huhndorf 2010), but later Hyde et al. (2013) and Wijayawardene et al. (2014b) accepted it as a genus in Platystomaceae. Thambugala et al. (2015b) accepted it as a genus in Lophiostomataceae. Platystomum shares many characters with Lophiostoma (Tanaka & Harada 2003b), but it has muriform ascospores, lacking a mucilaginous sheath or appendages (Thambugala et al. 2015b).