Description from Flora of China
Herbs, perennial, terrestrial, not rhizomatous. Stems branched or simple. Leaves few, along stem, alternate or opposite and strongly unequal; leaf blade glabrescent to sparsely puberulent, base strongly oblique, cuneate to rounded. Inflorescences lax, pseudoterminal, few- to many-flowered cymes; bracts 2, opposite. Calyx actinomorphic, 5-lobed, plicate between adjoining lobes; lobes equal. Corolla white, blue, or purple, zygomorphic, inside glabrous; tube campanulate, spurred or saccate at base, slightly longer than limb, ca. 4 mm in diam.; limb indistinctly 2-lipped; adaxial lip 2-lobed, nearly as long as abaxial lip; abaxial lip 3-lobed, lobes equal or subequal, apex rounded. Stamens 4, adnate to corolla tube near base, included; anthers basifixed, coherent laterally to form a shallow cone, thecae slightly divergent, confluent at apex, dehiscing longitudinally; connective not projecting; staminode unknown. Disc absent. Ovary subglobose, 1-loculed; placentas 2, parietal, projecting inward, 2-cleft. Stigma 1, terminal, broadly funnelform, undivided. Capsule straight in relation to pedicel, depressed-globose, shorter than calyx, dehiscing transversely or irregularly. Seeds unappendaged.
About 10 species: SE Asia, Pacific Islands; one species in China.