Sirosporium Bubák & Serebrian., Hedwigia 52: 273 (1912).
Associated with leaf spot. Sexual morph: Unknown. Asexual morph: Leaf spotting dematiaceous hyphomycetes with internal and external mycelium, superficial hyphae giving rise to solitary conidiophores, lateral and terminal. Conidiophores may also be formed in fascicles, conspicuous conidiogenous loci and hila, thickened and darkened. Conidia solitary, size, shape and septation variable, but the conidia are relatively thick-walled and at least partly dictyosporous (adapted from Braun et al. 2013; Videira et al. 2017).
Type species: Sirosporium antenniforme (Berk. & M.A. Curtis) Bubák & Serebrian.
Notes: Sirosporium is characterised by a passalora-like morphology with superficial hyphae, conspicuous conidiogenous loci and hila, solitary thick-walled conidia. In the phylogenetic analysis of Videira et al. (2017) based on LSU, ITS and RPB2, two Sirosporium species grouped in Mycosphaerellaceae in separate clades. The placement of Sirosporium in Mycosphaerellaceae is doubtful and the phylogenetic position is unresolved. Sequence data is available for S. celtidis (ITS, LSU, GAPDH, RPB2) and S. mori (ITS, LSU, GAPDH, TEF-1).