Scandent shrub, rarely a very small tree growing from a large tuberous rootstock. Stems cylindric, swollen at the nodes, rarely with tendrils. Leaves, alternate, elliptic to oblong, 2-8 cm long, hairless, lowermost pair of lateral veins starting at the base of the lamina, strongly smelling when crushed; margin serrate. Flowers in leaf-opposed, branched inflorescences, small, yellow or green. Fruit ovoid c. 1 cm long, purple to black when ripe.