Abstract
A molecular study of selected species of the genera Pseudorobillarda, Robillarda and Xepiculopsis was undertaken to determine their phylogenetic relationships. Based on the analysis of the LSU, SSU and ITS nrDNA, Xepiculopsis graminea belongs in the Hypocreales, grouping with Myrothecium and Didymostilbe (and its sexual morph Peethambara) with species of Stachybotrys in a sister clade, but cannot be assigned to any known family. Robillarda sessillis clusters with members of the Amphisphaeriaceae (Xylariales) but shows no affinity with any genus in that family. Pseudorobillarda species formed a monophyletic group within the Pleosporomycetidae (Dothideomycetes), but do not show affinity with any family or order. This study confirms that Pseudorobillarda and Robillarda are phylogenetically distantly related and a monographic treatment is warranted to resolve the position of other species assigned to these genera. Moreover, molecular data supports the introduction of a new family within the Hypocreales for a well supported clade with the genera Didymostilbe, Myrothecium, Stachybotrys and Xepiculopsis.