Hysterostomella Speg., Anal. Soc. cient. argent. 19(6): 260 (1885).
MycoBank number: MB 2476; Index Fungorum number: IF 2476; Facesoffungi number: FoF 02313; 25 morphological species (Species Fungorum 2020), molecular data unavailable.
Type species: Hysterostomella guaranitica Speg., Anal. Soc. cient. argent. 19(6): 260 [no. 305] (1885).
Notes: This genus is widely distributed throughout the tropics and is pathogenic on living leaves of palms (Inácio and Cannon 2008; Wijayawardene et al. 2018, 2020). Hysterostomella is characterized by circular or elliptical, flat, black ascostromata opening by irregular slits, with filamentous pseudoparaphyses above the asci, which are subglobose, obovoid, and clavate (Inácio and Cannon 2008).