Trees, shrubs or herbs. Leaves opposite, entire or crenate, united by a stipular line. Flowers in dence cymes, the cymes axillary or forming a terminal thyrsoid panicle; calyx campanulate, 4-toothed; corolla tubular, urn-shaped, with 4 lobes, imbricate in bud; stamen 4, inserted on corolla tube, anthers sessile; ovary 2-celled, style linear, clavate; ovules numerous in each cell. Fruit a septicidally 2-valved capsule; seeds very many, oblong or fusiform, slightly winged, with fleshy endosperm.
A genus of about 100 species widely distributed in tropical and subtropical Asia, Africa and America. Two species in Taiwan.
