Herbs or shrubs, rarely trees, erect, rarely scandent. Root usually thick, fleshy. Stems and branches terete, sulcate or angular, glabrous or young shoot and inflorescence pubescent. Leaves petiolate, rarely sessile; leaf blade ovate, elliptic, or lanceolate, apex acute or obtuse. Flowers pedicellate or sessile, in racemes, cymose panicles, or spikes, terminal or leaf-opposed. Tepals 5, persistent, spreading or reflexed, oblong to ovate, herbaceous or membranous, apex obtuse. Stamens 6-33, inserted at base of tepals; filaments subulate or linear, free or connate at base, included or exserted. Ovary subglobose, carpels 5-16, free or connate. Styles subulate. Fruit a fleshy berry, oblate. Seeds black, shiny, reniform, compressed; testa hard and fragile, smooth; tegument membranous.
About 25 species: nearly cosmopolitan, mostly native to South America, a few species in Africa and Asia; four species (one endemic, one introduced) in China.