Phytophthora castaneae, the correct name for P. katsurae nom. nov superfl.

Phytophthora katsurae was proposed as a nom. nov. for P. castaneae on the assumption that the replaced name was an illegitimate later homonym. This assumption was based on the invalid nomen nudum publication of Phytophthora castaneae in a host-pathogen index as a synonym of Mycelophagus castaneae, and an erroneous interpretation of Clements & Shear's listing of the type of the genus Mycelophagus. There is no valid earlier homonym. Phytophthora castaneae is the correct legitimate name for the taxon causing trunk rot of Castanea crenata, and P. katsurae is an illegitimate superfluous name.