Herbs, climbing, annual. Roots spreading. Tendrils simple. Plants dioecious. Male flowers in raceme or rarely solitary; calyx tube elongate, funnel-shaped; segments subulate; corolla broadly campanulate, 5-partite; segments entire; stamens 3, included in calyx tube; filaments free; anthers connate, one 1-celled, two 2-celled; anther cells linear, conduplicate; rudimentary ovary subulate. Female flowers solitary; calyx and corolla as in male flowers; staminodes 3, subulate or absent; ovary oblong, 3-locular, 4-6 ovules in each locule, pendulous; filaments filiform, elongate; stigmas 3, dilated. Fruit broadly oblong, 3-valved from apex nearly to base. Seeds pendulous, oblong or obovate, compressed, smooth, margins obtuse.