Tsugacorticium kenaicum (Hymenochaetales, Basidiomycota), a new corticioid genus and species from Alaska.

The new corticioid genus and species, Tsugacorticium kenaicum from Alaska, is described. Primarily found on attached, dead, corticate branches of mountain hemlock in the Kenai Peninsula, T. kenaicum is characterized by small, soft, white to yellow basidiomata, thickened subhymenium, much branched dendrohyphidia, and small globose to subglobose basidiospores. Although morphologically similar to Dendrothele (Agaricales) and Dendrocorticium (Corticiales), phylogenetic analyses of the nuclear large subunit ribosomal RNA gene place this taxon in the Rickenellaceae clade in the Hymenochaetales. Tsugacorticium kenaicum is described, illustrated, and compared to morphologically similar and phylogenetically related taxa.