Shrubs climbing [or herbaceous]. Stems slightly angled, glabrous. Petiole 4-8 cm, glabrate; leaf blade ovate-lanceolate, 10-17 × 4-5-6 cm, papery, abaxially sparsely gray villous, adaxially glabrous, veins palmate, 4-5 pairs from base, base auriculate, sinus 1-1.5 cm deep, apex acute. Flowers in axils of leafy shoots, solitary. Pedicel pendulous, 4-6 cm, sparsely pilose; bractlets ovate-lanceolate, ca. 5 × 2 mm, inserted above middle of peduncle. Calyx yellow-green; tube geniculately curved, abaxially sparsely pilose to glabrous; basal portion of tube 15-20 × 3-4 mm; limb saccate, ovoid, asymmetric, 1-2 × 0.3-1.5 cm, 3-lobed; lobes ovate-deltate, ca. 4 × 5 mm, erect, papillate. Anthers oblong, ca. 2 mm. Gynostemium 3-lobed. Fruit not seen. Fl. Apr.