Description from Flora of China
Stems 10-22 cm, sparsely puberulent, glabrescent, simple, several borne from a node of rhizome. Leaves opposite, spread along stem, unequal to subequal in a pair; petiole 0.5-3 cm, sparsely pubescent; leaf blade elliptic or nearly so, 7-24.5 X 3-10.5 cm, glabrous, abaxially sparsely puberulent along veins, base oblique, cuneate to slightly rounded, margin entire to indistinctly denticulate, apex acuminate. Cymes branched 2-5 , 3-10-flowered; peduncle 6-13.5 cm, sparsely puberulent; bracts lanceolate to oblong, 2-5 X 0.6-1.5 mm, margin entire. Pedicel 0.5-2.5 cm. Calyx 5-sect from near base; segments equal, lanceolate to triangular, 5-7 X 1-2 mm, margin entire. Corolla white, inside purple, 2.5-4 cm, outside pubescent, inside glabrous; tube 2.2-3.5 X 1.3-1.7 cm; adaxial lip lobes semiorbicular, 5-6 X 5-6 mm; abaxial lip ca. 7 mm, lobes semiorbicular, 5-6 X 7-10 mm. Adaxial stamens ca. 8 mm, abaxial ones ca. 1 cm, glabrous; staminode ca. 0.5 mm. Pistil 2-2.1 cm; ovary densely puberulent to glandular pubescent. Style ca. 1.2 mm, minutely pilose to densely glandular pubescent. Capsule 7.5-8 cm. Seed appendages 0.4-0.5 mm. Fl. Oct.
* Trees, limestone cliffs; ca. 1200 m. SW Guangxi (Napo Xian), Guizhou (Zhenfeng Xian), SE Yunnan (Hekou Xian).