Pileate Fomitiporia species in the USA. New combinations Fomitiporia calkinsii and F. bakeri

Sequencing of the ribosomal ITS region was used to resolve the relationship among USA collections of the morphological species Fomitiporia robusta. F. robusta corresponding to European collections was not found and its occurrence in the USA is regarded as questionable. Birch-growing fungus from mid-western and eastern United States known as Phellinus bakeri is a closely related polypore, but because of the absence of typical F. robusta here, it should be considered a separate species. Oak-growing pileate fungus from the south-eastern USA, also known as Fomes calkinsii, is a distinct species, rather distant from the European F. robusta. New combinations Fomitiporia bakeri and F. calkinsii are proposed. Notes on other similar species are provided.