Herbs twining. Stems terete, striate, glabrous. Petiole 1-2 cm, glabrous; leaf blade polymorphic, ovate or ovate-deltate to sagittate, 2.5-5.5 × 2-6 cm, papery, both surfaces glabrous or abaxially villous, veins palmate, 1-2 pairs from base, base cordate or broadly cuneate, usually deeply 3-lobed, lateral lobes obovate or semiround, 7-20 × 5-15 mm, middle lobe rhombic or ovate-lanceolate to linear-lanceolate, 1.5-5 × 0.5-1.5 cm, apex acute. Racemes in axils of leafy shoots, 2-4 flowered, 2-4 cm. Pedicel ascending, 0.2-0.5 cm, sparsely pilose; bractlets ovate-deltoid, 2-5 × 2-4 mm, inserted near base of pedicel. Calyx dark purple; tube rectilinear, abaxially glabrous; utricle globose, ca. 4 mm in diam., with stipe 2-3 mm; tube 5-7 × 1.5-2 mm; limb unilateral, ligulate, oblong, ca. 1.5 × 0.4 cm, apex obtuse. Anthers elliptic, 0.3-0.4 mm. Gynostemium 6-lobed. Capsule subglobose, ca. 1.5 cm in diam., dehiscing acropetally. Seeds ovoid, 2.5 × 2 mm. Fl. Oct-Dec, fr. Jun-Aug.

* Forests; below 100-200 m. Hainan.