Description from Flora of China
Herbs twining. Stems angled, densely white or brown villous. Petiole 2-8 cm, densely villous; leaf blade cordate to ovate-cordate, 4-11 × 4-11 cm, papery, both surfaces white or brown villous, veins palmate, 2-3 pairs from base, base cordate, sinus 1-1.2 cm deep, apex acute. Racemes in axils of leafy shoots, 3- or 4-flowered, 1-3 cm. Pedicel erect to ascending, 0.5-1.5 cm, sparsely pilose; bractlets ovate or ovate-cordate, 5-10 × 5-7 mm. Calyx green with green veins, limb dark purple; tube rectilinear or slightly curved, abaxially sparsely pilose; utricle globose, ca. 4 mm in diam., sessile; tube ca. 2.5 × 2 mm; limb unilateral, ligulate, ovate-lanceolate, 0.8-1.6 × ca. 0.5 cm, apex long acuminate with twisted cauda 1-1.5 cm. Anthers elliptic, ca. 0.5 mm. Gynostemium 6-lobed. Capsule cylindric to obovoid, ca. 2 × 1 cm, dehiscing acropetally. Seeds ovoid-triangular, ca. 3 × 3 mm. Fl. Mar-Apr, fr. May-Aug.
* Thickets, on mountain slopes, roadsides. Fujian, Zhejiang.