Twiners woody; axial parts glabrous or grayish yellow tomentose. Stems terete, fistulose. Petiole 4.5-12 cm; leaf blade nearly circular, rarely broadly ovate, 9.5-15.5 X 7-14 cm, glabrous or puberulent along veins abaxially, base cordate, margin entire, apex abruptly acuminate or cuspidate. Inflorescences corymbose cymes, many flowered; peduncle 5-24(-35) cm, terete and glabrous basally, slightly applanate distally, dull yellow pubescent, sometimes entirely grayish yellow tomentose; bracts early deciduous, narrowly triangular, 1.5-2 mm, densely yellowish pubescent. Pedicel 1-2 cm, enlarged in fruit. Sepals ± equal or outer ones slightly shorter, 6-13 mm; outer 2 broadly ovate, abaxially dull yellow pubescent; inner 3 nearly circular, glabrous, apex obtuse. Corolla yellow, broadly funnelform or campanulate, 1.4-2(-3.2) cm, midpetaline bands yellowish sericeous outside; limb undulate. Stamens included; filaments with 2 longitudinal pubescent lines below insertion; anthers belatedly twisted. Ovary conical, glabrous. Capsule brown, fading to yellow apically, conical-ovoid, 1-1.2 cm, glabrous. Seeds broadly trigonous-ovoid, ca. 5 mm, densely scaly pubescent along angles.

Forests; 100-1300 m. Guangxi, Hainan, Yunnan [Indonesia, Laos, Vietnam]