Clarohilum Videira & Crous, in Videira et al., Stud. Mycol. 87: 334 (2017).
Index Fungorum number: IF 822583; Facesoffungi number: FoF 08487, 1 morphological species (Species Fungorum 2021), 1 species with molecular data.
Phytopathogenic, causing leaf spots. Sexual morph: Ascomata globose, subepidermal, mostly epiphyllous, brown or dark brown, ostiolate, thin wall composed of pseudoparenchymatous cells. Asci cylindrical, tapering towards the base, bitunicate, thick-walled, 8-spored. Ascospores hyaline, tapering at both ends, two-celled with the upper cell slightly broader than the lower. Asexual morph Conidiophores mononematous, pale olivaceous brown, not branched, with slight geniculations, septate. Conidiogenous cells terminal, elongating sympodially, polyblastic, with conidiogenous loci thickened and darkened, located both apical and laterally. Conidia single, pale olivaceous, smooth, obovoid, obclavate, cylindrical to long-obclavate, slightly curved, apex obtuse, base rounded or short obconicaly truncate, septate, hila thickened, darkened and usually protruding (Adapted from Videira et al. 2017).
Type species: Clarohilum henningsii (Allesch.) Videira & Crous
Notes: Clarohilum was introduced by Videira et al. (2017) with C. henningsii as type species. Clarohilum is characterized by globose, subepidermal ascomata, cylindrical asci, hyaline ascospores. The type species, C. henningsii previously known as Passalora henningsii has paler caespituli compared to other species of Passalora sensu lato and has conidia with distinctly protruding hila. In the phylogenetic analysis of Videira et al. (2017), Clarohilum forms a single lineage close to Nothopassalora. Clarohilum differs from Nothopassalora in having less protruding hila that tapered towards the base like some of the conidia. Clarohilum is a distinct and well-supported genus in Mycosphaerellaceae.