common horse-shoe vetch, in botany: A genus of the decandria order, belonging to the diadelphia clas of plants; and in the natural method ranking under the 32d order, Papilionaceae. The legumen is compressed and crooked, with many incisions on the interior future. There are three species, two natives of the warm parts of Europe, and one of Britain. They are all low herbaceous trailing plants, with yellow flowers. They are propagated by seeds; but having no great beauty are seldom kept in gardens.