Melampyrum is a genus of about 20 species of herbaceous flowering plants in the family Orobanchaceae known commonly as cow wheat. They are native to temperate regions of the Northern Hemisphere. They are hemiparasites on other plants, obtaining water and nutrients from host plants, though they are able to survive on their own without parasitising other plants. Melampyrum species are used as food plants by the larvae of some Lepidoptera species, including the mouse moth (Amphipyra tragopoginis).