Peniophora is a genus of fungi which are plant pathogens. Members of the genus belong to the class Basidiomycetes, order Russulales, and family Peniophoraceae. The genus is widespread, and contains 62 species. The species of Peniophora are resupinate, or crust-like, and are described as corticioid. A number of its members are parasitised by other fungi. For example, Tremella mesenterica is a parasite to several species of Peniophora.