Skyttea richardsonii sp. nov. from Maine, with a key to the species known from North America.

Skyttea richardsonii sp. nov. is described from a sterile corticolous lichen in Maine. It is closest to S. tavaresae, the only other member of the genus to be reported as having annelations on the excipular hairs, but that species occurs on Loxospora spp. and differs in the K+ reaction of the exciple and ascospore size. Minute Phoma-like conidiomata found in some apothecia may represent an independent fungicolous fungus growing on the new species. This is the 10th species of the genus to have been discovered in North America; a key to these species is provided.