Description from Flora of China
Shrubs or trees, erect or rarely climbing; hairs stellate, verticillately branched, dendritic, mealy tomentose, or rarely simple and hooked. Branchlets terete or 4-angled. Leaves opposite or in 3s. Cymes axillary, sessile or pedunculate; bracts linear. Calyx campanulate, truncate or minutely 4-dentate, unaltered in fruit. Corolla actinomorphic, campanulate or tubular, lobes 4. Stamens 4, inserted on corolla tube; filaments slender, often exserted; anthers ovate or oblong, dehiscing by longitudinal slits or circular pores. Ovary imperfectly 2-locular; ovules 2 per locule, attached to middle or distal part of ovary. Style usually longer than stamens; stigma usually dilated. Fruit a small globose drupe, endocarp bony, mesocarp fleshy, exocarp thin. Seeds small, oblong; seed coat membranous; cotyledons fleshy.
About 140 species: mainly in tropical and subtropical Asia, few in tropical America and Africa, and very few in temperate Asia and North America; 48 species in China.