Subshrubs, epipetric or terrestrial, not rhizomatous. Stems branched from base or simple. Leaves few to many, opposite, equal to subequal in a pair; leaf blade puberulent, base cuneate. Flowers solitary, axillary; bracts 2, opposite. Calyx actinomorphic, 5-sect from base; segments equal. Corolla purple to blue or white to pale yellow, zygomorphic, inside glabrous; tube campanulate-tubular, not swollen, longer than limb, 0.7-1.3 cm in diam.; limb 2-lipped; adaxial lip 2-lobed, slightly shorter than abaxial lip; abaxial lip 3-lobed, lobes subequal, apex rounded. Stamens 2, adnate to abaxial side of corolla tube near middle, included; anthers dorsifixed, coherent, thecae divaricate, confluent at apex, dehiscing longitudinally; connective projecting slightly; staminodes 2, adnate to adaxial side of corolla tube. Disc ringlike. Ovary narrowly oblong, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Stigmas 2, unequal, subsemiorbicular to ligulate or ringlike, emarginate. Capsule straight in relation to pedicel, narrowly oblong to nearly linear, much surpassing calyx, dehiscing loculicidally to base; valves 2, spirally twisted. Seeds unappendaged.

* One species: endemic to China.