Aporpium Bond. and Singer, was originally regarded as a polypore, as suggested by its poroid hymenium and tough texture. The basidia are, however, cruciate-septate. The single species, A. caryae (Polyporus c. Schw.) has been named several times and has always been grouped with the poroid Homobasidiomycetes. A revised description and synonymy are given, and distribution is indicated.