Podosphaera fusca is a fungus that parasitically infects plants (a phytopathogen). It is one cause of powdery mildew in melons and gourds. Some sources suggest that P. fusca should be considered synonymous with P. xanthii, while others maintain they are separate species in the Magnicellulata subsection of the Sphaerotheca section of the Podosphaera genus, as of 2011, based on the size of chasmothecia, and on the thin-walled portion of the asci (oculus).