CARPINUS, the HORN-BEAN, in botany, a genus of the monœcia polyandria class. The calix of the male is bell-shaped, and divided into five segments; it has no corolla; and the stamens are ten. The calix of the female has four teeth; there is no corolla; the styli are three; and the capsule has four valves, containing two seeds. There are but two species, both natives of America.