Molecular taxonomy of Dinemasporium and its allied genera

• Dinemasporium, Diarimella and Stauronema were revised taxonomically.
• Diarimella and Stauronema were synonymized under Dinemasporium.
• An expanded generic concept of Dinemasporium was proposed.
• Morphology of conidial appendages was phylogenetically insignificant for generic definition.
• Eight new species of Dinemasporium were described.

The taxonomic relationships of three coelomycetous genera, Dinemasporium, Diarimella and Stauronema, were assessed. A total of 43 isolates/specimens of Dinemasporium-like fungi were examined by phylogenetic analysis of internal transcribed spacer sequences of the nuclear rRNA gene and morphological comparisons. Species highly consistent with Diarimella or Stauronema generic concepts failed to form monophyletic groups, but were scattered within the Dinemasporium clade. Diarimella and Stauronema are therefore treated as synonyms of Dinemasporium. An expanded generic concept of Dinemasporium is proposed to accommodate species having conidia with bipolar and lateral appendages (formerly Stauronema) or branched multiple appendages (formerly Diarimella), as well as typical Dinemasporium species having conidia with bipolar unbranched appendages. Eight new species of Dinemasporium — D. ambiguum, D. bambusicola, D. iriomotense, D. japonicum, D. parastrigosum, D. pseudodecipiens, D. rishiriense and D. sasae — are described and illustrated.