Cheirosporium gen. nov. is characterised by the production of sporodochial conidiomata, semi-macronematous to macronematous conidiophores that possess several distinct sterile branches, and cheiroid, smooth-walled conidia with rhexolytic secession. The 28S rDNA and ITS rDNA operon of this taxon were amplified and sequenced. A BLAST search revealed low homology between Cheirosporium triseriale and existing sequences in public databases, supporting the hypothesis that the species is new to science. Phylogenetic analysis showed that C. triseriale groups with Dictyosporium and allied species, and nests within the Pleosporales (Dothideomycetes, Ascomycota). Cheirosporium is morphologically distinct from the cheirosporous genera Cheiromyces, Cheiromycina, Dictyosporium, Digitomyces, Digitodesmium and Pseudodictyosporium and these differences are discussed.
Keywords: Pleosporales; ascomycetes; systematics; taxonomy.