Exserohilum K.J. Leonard & Suggs, Mycologia 66(2): 289 (1974).
Saprobic or pathogenic on leaves or wood. Sexual morph: Ascomata superficial, globose or ellipsoid with or without an ostiole. Ostiole surrounded by simple, short, rigid, brown hairs, similar hairs scattered over surface of upper part of ascomata. Peridium coriaceous-carbonaceous, pseudoparenchymous. Pseudoparaphyses filamentous. Asci 1–8-spored, bitunicate, cylindrical to cylindrical-clavate. Ascospores hyaline, fusoid, trans-septate, surrounded by a mucilaginous sheath. Asexual morph: Conidiophores cylindrical, simple, olivaceous brown, upwardly geniculate. Conidia porogenous, acrogenous and pseudopleurogenous, subcylindrical to fusoid or broad obclavate-rostrate, pseudoseptate, olivaceous to brown, hilum protruding from basal cell, germinating by bipolar germ tubes (Adapted from Ariyawansa et al. 2015).
Type species: Exserohilum turcicum (Pass.) K.J. Leonard & Suggs
Notes: Exserohilum was introduced by Leonard and Suggs with E. turcicum as type species. Exserohilum accommodated species which were previously classified in Bipolaris characterized by distinctly protuberant conidial hilum. In the same study, the sexual morphs of Exserohilum which is distinct from Keissleriella based on the absence of clypeus, lysigenous development of the ostiole, presence of setae on the perithecial wall, the absence of periphyses in the ostiole and the hyphomycetous conidial states was placed in a new genus, Setosphaeria. Considering the one fungus-one name rule, Wijayawardene et al. (2014) suggested to use Exserohilum over Setosphaeria.