Description from Flora of China
Herbs twining. Stems terete, striate, glabrate. Petiole 6-10 cm, glabrous; leaf blade ovate to ovate-deltate, 6-16 × 5-11 cm, leathery or papery, aromatic-punctate, abaxially puberulous, hairs on veinlets forming closely foveolate reticulation, adaxially glabrous, veins palmate, 2-3 pairs from base, base deeply cordate, sinus 1.5-2 cm deep, apex acute. Racemes in axils of leafy shoots, 8-10-flowered, 4-6 cm. Pedicel ascending to slightly pendulous, 0.8-1.2 cm, glabrous; bractlets ovate, ca. 1.5 × 1 cm, base cordate and slightly amplexicaul. Calyx yellowish green, limb dark purple; tube rectilinear or slightly curved, abaxially glabrous; utricle globose, ca. 3 mm in diam., sessile; tube ca. 10 × 1.5 mm; limb unilateral, ligulate, ovate-lanceolate, ca. 1.5 × 0.5 cm. Anthers elliptic, ca. 0.5 mm. Gynostemium 6-lobed. Fruit not seen. Fl. Mar-Apr.
* Forests on mountain slopes; 1000-1300 m. Guangxi, Yunnan.