a genus of the didynamia angiospermia clas. The calyx has four segments; the upper lip of the corolla is compressed, and bent back at the edge; and the capsule has two oblique cells containing two gibbous seeds. There are five species, four of them natives of Britain, viz. the cristatum, or crested cow-wheat; the arvense, or purple cow-wheat; the pratense, or meadow cow-wheat; and the sylvaticum, or yellow cow-wheat.