Description from Flora of China
Herbs, probably perennial, terrestrial. Rhizomatous. Stems simple or branched. Leaves few to many, along stem, opposite, equal to subequal in a pair; leaf blade densely pubescent to velutinous, base cuneate to rounded. Inflorescences sympodial, spikelike, dense, ca. 10-flowered cymes axillary near stem apex; bracts 2, opposite. Calyx nearly actinomorphic, 5-lobed; adaxial central lobe larger. Corolla white, zygomorphic, inside glabrous; tube funnelform, not swollen, longer than limb, ca. 9 mm in diam.; limb 2-lipped; adaxial lip 2-lobed, much shorter than abaxial lip; abaxial lip 3-lobed, lobes unequal, apex rounded. Stamens 2, adnate to abaxial side of corolla tube near middle, included; anthers basifixed, coherent at apex, thecae parallel, not confluent at apex, dehiscing longitudinally; connective not projecting; staminodes 2 or 3, adnate to adaxial side of corolla tube. Disc cupular. Ovary linear, 1-loculed; placentas 2, parietal, slightly projecting inward, 2-cleft. Stigmas 2, unequal, smaller 1 truncate, undivided, larger 1 narrowly obtrapeziform, emarginate. Capsule straight in relation to pedicel, linear, much longer than calyx, dehiscing loculicidally to base; valves 2, straight, not twisted. Seeds unappendaged.
One species: China, Vietnam.