Climbers to 12 m tall. Branches puberulent when young, glabrescent. Petiole 0.8-2 cm, abaxially grooved, glabrous; leaf blade oblong, 14-30 × 5.5-12 cm, papery, abaxially puberulent when young but glabrescent and greenish with age, adaxially dark green and glabrous, secondary veins 15-20 on each side of midvein and adaxially flat, reticulate veins conspicuous, base truncate to shallowly cordate, apex shortly acuminate. Inflorescences leaf-opposed or subopposed, cymose, 2-8-flowered; peduncle 1-2 mm; bracts ovate, pubescent. Pedicel 0.5-2.3 cm, fulvous pubescent, bracteolate at middle. Flower buds broadly ovoid. Sepals triangular, ca. 4 × 4 mm, outside pubescent. Petals yellowish white; outer petals ovate-oblong, ca. 12 × 5(-10) mm, outside fulvous pubescent, inside glabrous; inner petals ovate-triangular, ca. 8(-11) × 4(-7) mm, outside pubescent, inside glabrous. Stamens oblong, ca. 1.2 mm; connectives apically rounded. Carpels ca. 15, ovate-oblong, 2-3 mm, densely pubescent; ovules 10 per carpel, in 2 series; styles short; stigmas ellipsoid, apex entire. Fruiting monocarps globose, subglobose, ellipsoid, or obovoid, 3.5-6 × 3.5-4 cm, glabrous. Seeds 10-20 per monocarp, in 2 series. Fl. Mar-Nov, fr. Jul-Dec.