Tritirachium, commonly regarded as a member of the Ascomycota, is an anamorph producing sympodulate conidia. The purpose of this study was to examine the phylogenetic relationships between this fungus and some presumably related taxa. Phylogenetic analyses of DNA sequences coding for the small ribosomal subunits of some Tritirachium species revealed their basidiomycetous nature. The topologies showed that they represent a highly supported clade in the Basidiomycota. The morphologically similar Nodulisporium cylindroconium, previously described as 'Tritirachium sp A', clustered with the Tritirachium species within the Pucciniomycotina. It could not be retained in Tritirachium because of its different conidiogenesis. Consequently, a new genus, Paratritirachium, is proposed for it. -® 2012 J. Cramer in Gebr. Borntraeger Verlagsbuchhandlung, Stuttgart, Germany