Description from Flora of China
Shrubs small, terrestrial, not rhizomatous. Stems branched or simple. Leaves usually few, along stem, opposite, seldom alternate, equal to subequal in a pair; leaf blade surfaces sericeous to hirsute or woolly, often glabrescent, base attenuate to rounded. Inflorescences lax, axillary, (few)- to many-flowered cymes; bracts 2, opposite. Calyx actinomorphic, 5-sect from base; segments equal. Corolla white to reddish or purple, zygomorphic, inside glabrous; tube campanulate tubular, not swollen, shorter than limb, 1-2 mm in diam.; limb indistinctly 2-lipped; adaxial lip 2-lobed, shorter than to equalling abaxial lip; abaxial lip 3-lobed, lobes equal or subequal, apex rounded to obtuse. Stamens 4, adnate to corolla tube near base or rarely near middle, included; anthers basifixed, free, thecae parallel, confluent at apex, dehiscing longitudinally; connective not projecting; staminode absent or 1, adnate to adaxial side of corolla tube. Disc ringlike or absent. Ovary ovoid, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Stigma 1, terminal, depressed globose, undivided. Berry ovoid to globose, slightly longer than calyx, indehiscent. Seeds unappendaged.
About 13 species: SE Asia, Pacific Islands; five species in China.