Herbs (outside China), shrubs, or seldom small trees, perennial, terrestrial, not rhizomatous. Stems branched or simple. Leaves usually few, along stem, opposite, whorled, or rarely alternate, equal to subequal in a pair; leaf blade glabrous to densely pubescent, pilose, villous, or sericeous, base attenuate to cuneate, rarely to cordate. Inflorescences lax or dense, axillary or rarely cauliflorous, 1- to many-flowered cymes; bracts 2 or absent, opposite. Calyx actinomorphic or zygomorphic; 2-5(or 6)-lobed; lobes equal to unequal. Corolla white to yellow, occasionally green, orange, reddish, or purplish, zygomorphic or rarely actinomorphic, inside glabrous to pubescent; tube campanulate to salverform, funnelform, or cylindric, not swollen, usually much longer than limb; limb usually 2-lipped; adaxial lip 2-lobed, shorter than to slightly exceeding abaxial lip; abaxial lip 3-lobed, lobes equal or central lobe longer, apex rounded or obtuse, rarely acute. Stamens 2, adnate to abaxial side of corolla tube near middle, usually included; anthers basifixed to dorsifixed, coherent or free, thecae slightly divergent to divergent, confluent or not, dehiscing longitudinally; connective not projecting or apiculate; staminodes 2 or 3, adnate to adaxial side of corolla tube. Disc ringlike or rarely cupular. Ovary ovoid to oblong, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Stigma 1, terminal, capitate to ovoid or obtriangular, undivided or sometimes 2-lobed. Berry fleshy to leathery, ovoid to oblong, slightly longer to shorter than calyx, indehiscent. Seeds unappendaged.

About 350-600 species: SE Asia, Pacific Islands; one species in China.