Colletogloeum Petr., Sydowia 7(5–6): 368 (1953).
Index Fungorum number: IF 7733; Facesoffungi number: FoF 08596, 15 morphological species (Species Fungorum 2022), 1 species confirmed, molecular data available for some unnamed species in the genus
Mycelium immersed, branched, septate, hyaline to pale brown. Sexual morph: Unknown. Asexual morph: Conidiomata acervular, epidermal to subepidermal, separate, occasionally confluent, composed of pale brown to hyaline, thin-walled textura angularis. Dehiscence irregular. Conidiophores hyaline or very pale brown, sparsely branched, septate, smooth, cylindrical or slightly irregular, formed from the upper cells of the acervulus. Conidiogenous cells holoblastic, annellidic, integrated or discrete, indeterminate, cylindrical or doliiform, with several percurrent proliferations. Conidia hyaline or pale brown, 0- to multiseptate, straight, curved or irregular, truncate at the base, obtuse at the apex, usually thin-walled, smooth, guttulate or eguttulate (adapted from Videira et al. 2017).
Type species: Colletogloeum dalbergiae (S. Ahmad) Petr.
Notes: Colletogloeum is characterised by acervular, epidermal to subepidermal conidiomata, hyaline or very pale brown conidiophores, holoblastic, annellidic, integrated conidiogenous cells and hyaline or pale brown, 0- to multiseptate conidia. Colletogloeum dalbergiae was previously known as Septogloeum dalbergiae but was not congeneric with the type species S. carthusianum. Sutton (1964) emended Colletogloeum to accommodate species only with annellate conidiophores. Colletogloeum resembles Ahmadia but differs in having an epidermal to subepidermal conidiomata while species of Ahmadia have subcuticular conidiomata. Colletogloeum is also similar to Phloeospora in comprising species with hyaline conidia. Colletogloeum is an asexual genus with “Mycosphaerella”-like sexual morphs (Sutton 1980; Verkley and Priest 2000). Crous et al. (2009e) extracted DNA from type species, Colletogloeum sissoo (IMI 119162) and reported that Colletogloeum is closely related to Pseudocercospora based on phylogenetic analysis of ITS sequence data. The placement of Colletogloeum in Mycosphaerellaceae is doubtful. The generic placement of Colletogloeum must be confirmed based on more taxa with DNA sequence data. Only ITS sequence data is available for Colletogloeum sissoo (IMI 119162).