Melampyrum lineare is one of the more quietly subversive plants in the eastern North American flora. Its small tubular flowers, white with yellow throats and oddly pinched at the mouth, appear in summer beneath pine canopies and along rocky barrens from Canada south through the Appalachians. The genus name translates as "black wheat," a nod to the dark seeds found in related species. It grows in dry to moist acidic soils and partial shade, often in association with pine, blueberry, and other ericaceous plants — not by coincidence, but by parasitism.

Cow-wheat is hemiparasitic, meaning it photosynthesizes on its own but also uses specialized root structures to tap into neighboring roots and extract water and nutrients. This makes it nearly impossible to grow in isolation; it needs a host community to persist, which limits its use to naturalistic woodland gardens where its host plants are already established. It is an annual that sets seed and disappears, leaving next year's plants to germinate where conditions allow. No serious pests or diseases are reported, and in the right woodland setting it seeds around unobtrusively, never becoming a nuisance.