in botany, a genus of the dioecia pentandra clas. The calyx of the male is divided into five parts, and it has no corolla. The calyx of the female consists of one entire leaf opening at one side; the corolla is wanting; it has two styli; and the nut has two valves, and is inclosed within the calyx. There is but one species, viz. the lupulus, or hop, a native of Britain. See Hop.