Description from Flora of China
Herbs, annual, terrestrial or epipetric, not rhizomatous. Stems simple or branched. Leaves few, along stem, opposite, equal to subequal in a pair; leaf blade glabrous to pubescent, base cuneate to rounded. Inflorescences often racemelike, lax, axillary, 2-10-flowered cymes sometimes near stem apex; bracts 2, opposite. Calyx actinomorphic, 5-sect from base; segments equal. Corolla white to purplish, zygomorphic, inside glabrous; tube slender funnelform, not swollen, longer than limb, 0.7-1.3 cm in diam.; limb 2-lipped; adaxial lip 2-lobed, much shorter than abaxial lip; abaxial lip 3-lobed, lobes subequal, apex rounded. Stamens 2, adnate to abaxial side of corolla tube near mouth, slightly exserted; anthers basifixed, coherent at apex, thecae parallel, not confluent at apex, dehiscing longitudinally; connective not projecting or projecting; staminodes 2 or 3, adnate to adaxial side of corolla tube. Disc ringlike. Ovary linear, 1-loculed; placentas 2, parietal, slightly projecting inward, 2-cleft. Stigmas 2, equal, oblate or semiorbicular, undivided. Capsule straight in relation to pedicel, linear, much longer than calyx, dehiscing loculicidally to base; valves 2, straight, not twisted. Seeds unappendaged.
* Two species: endemic to China.