Tectobasidium (incertae sedis, Basidiomycota), a new genus for T. chlamydosporum, comb. nov., and T. cornutum, sp. nov

A new genus, Tectobasidium, is described to accommodate T. chlamydosporum, comb. nov. (= Achroomyces chlamydosporus), and T. cornutum, sp. nov. Both species possess two-celled basidia and cylindrical basidiospores, as well as characteristic, thick-walled and cyanophilous chlamydospores. Tectobasidium spp. develop in the living basidiocarps of other basidiomycetes (Helicogloea and Myxarium) as intrahymenial fungi. No signs of the parasitic habit have been detected for them, although a mycoparasitic strategy cannot be completely ruled out. nc LSU rDNA-based phylogenetic inference places Tectobasidium at the very base of the subphylum Ustilaginomycotina, with moderate (BI) or strong (ML) support. Due to the lack of additional DNA, ultrastructural, and cultural data, we leave the suprageneric classification of Tectobasidium unresolved.