Vigorous liane with twining puberulent stems. Petioles to c. 4 cm long, densely puberulent or whitish tomentulose. Lamina 2.7-12 × 1.5-6 cm, ovate-oblong or oblong, dark green and becoming glabrous above except for midrib, glaucous-white tomentulose beneath; base deeply cordate with acute sinus, or truncate on flowering shoots; apex rounded and mucronate. Fls usually 2-4. Peduncles and pedicels to c. 1.5 cm long, tomentulose. Bracts usually < longer pedicels, linear or linear-oblong. Calyx 8-15 mm long; segments ovate, imbricate, tomentulose. Corolla (1.7)-2-2.5 × 1.5-2 cm, deeply campanulate, white, sometimes strongly streaked with pinkish mauve inside. Gynostegium 1/2-⅔ length of corolla tube. Follicle to 10-(12) × 7 cm, oblong-ovoid or ovoid, green, thick and leathery, minutely tomentulose, with carpel groove down inner face. Seeds 7-8 mm long, oblong-spathulate, dark brown, tuberculate; silken apical tuft 3-5 cm long.