Vines, climbing, herbaceous. Stem and branches angular-sulcate, pubescent and white setose at first, later glabrescent. Petiole 4-8 cm; leaf blade broadly ovate-cordate, 6-12 × 4-10 cm, undivided, abaxially pubescent, adaxially scabrous, densely setose, margin dentate, apex shortly acuminate or acute; basal sinus open, semicircular, 5-15 mm deep, 10-25 mm wide. Tendrils filiform, simple or 2-fid. Male flowers dimorphic, solitary one larger, smaller ones in a raceme; pedicel slender, 10-18 mm, pubescent; calyx pubescent; tube broadly campanulate, 3-4 mm; segments lanceolate, 4-6 mm, 3-veined, apex acuminate; corolla segments ovate, 10-12 × 5-6 mm, apex acute; filaments 2-2.5 mm; anthers elliptic, 3-3.5 mm. Female flowers solitary or binary; pedicels 5-10 mm; calyx and corolla as in male flowers; corolla segments obovate, 20-25 × ca. 10 mm, apex slightly obtuse; staminodes 5, sparsely puberulent, apex slightly enlarged; ovary fusiform, densely villous; style 3-fid, ca. 2 mm; stigma enlarged, 2-lobed.

● Mountain slopes, roadsides; 1800-2400 m. E Shaanxi, S Shanxi.