Vines, climbing, herbaceous. Stems and branches slender, angular-sulcate, at first densely pubescent, glabrescent. Petiole 4-8 cm; leaf blade narrowly ovate-cordate, 10-16 × 6-11 cm, membranous, adaxially scabrous, with setae on an enlarged base, veins densely pubescent, basal vein along margin of base of leaf, base cordate, margin dentate, apex shortly acuminate; sinus at base open, semicircular, 1-2 cm deep, 0.5-1 cm wide. Male flowers: 5-9 in pedunculate raceme; bracts flabelliform, 12-15 × 15-17 mm, both surfaces pubescent, margin irregularly dentate; pedicels slender, 5-10 mm, pubescent; calyx tube campanulate, ca. 4 mm; segments broadly lanceolate to narrowly ovate, slightly irregular, ca. 1.5 cm × 4-6 mm, distinctly 3-veined, apex usually irregularly 2- or 3-lobed; corolla segments narrowly oblong, ca. 2 × 1 cm, apex shortly acuminate; filaments pubescent; rudimentary ovary semiglobose. Female flowers solitary; pedicels 2-5 cm, pubescent; calyx segments broadly lanceolate or narrowly ovate, to 18 × ca. 6 mm, 3-veined, margin often 2- or 3-lobed, apex acuminate; corolla segments ca. 3 × 1.4 cm; ovary narrowly oblong, 15-18 × 4-6 mm, densely yellow villous, base narrow, apex subtruncate; style filiform, 3-fid; stigma enlarged, 2-lobed. Fruiting pedicel robust, 3-5 cm, subglabrous; fruit elliptic, 2.5-3 × ca. 1.5 cm, pubescent, obtuse at both ends. Fl. Jun-Aug, fr. Aug-Oct.

● Mountain slopes, forests; 2100-2400 m. Yunnan.