Plants annual. Stem and branches slender. Tendrils filiform. Petiole 3.5-7.5 cm; leaf blade broadly ovate-cordate, 5-9 × 3-7 cm, membranous, usually 2- or 3-angled on each side, both surfaces glabrous, palmately 5-7-veined, margin dentate, apex acuminate; sinus semicircular. Plants dioecious. Male flowers in a raceme; peduncle filiform, 5-10 cm; pedicels filiform, 2-3 mm; calyx segments linear-subulate or narrowly lanceolate, 1-1.2 × 0.5-0.8 mm; corolla white, rotate; segments lanceolate or oblong-lanceolate, 2-3.5 × 1.5-2 mm, 1-veined; filaments connate, ca. 0.8 mm; anthers free or united only at base, ca. 0.5 mm; connective not produced. Female flowers solitary or a few aggregated at apex of a short peduncle; ovary ovoid, glabrous or pubescent, apex shortly acuminate, 3-locular, 1 ovule in each locule; styles 3-fid; stigma slightly expanded. Fruiting pedicel filiform, 1-2 cm; fruit pale brown to black-brown when mature, broadly ovoid, ca. 1.2 cm × 8 mm, glabrous or pubescent, smooth or verrucose, base rounded, apex acute, 3-valved from apex, usually with 2 seeds. Seeds pale brown when mature, ovoid, ca. 8 × 5 mm, base slightly wider, ca. 2 mm thick, irregularly dentate, contracted above, apex truncate.

● Grasslands, thickets, and roadsides on mountain slopes; 1000-2400 m. Guizhou, W Hubei, NW Hunan, S Shaanxi, E and W Sichuan.