Perennial climbers with unbranched, glabrous tendrils, dioecious. Root tuberous. Leaves broadly ovate, membranous, c. 6.0 x 5.0 cm, glabrous on both sides, deeply 3-5-lobed, lobes trianglular ovate or oblong, acute, with undulate or minutely remotely denticulate margin; petiole 1-3 cm long, puberulous. Male flowers 5-6 cm across, yellow, on 4-6 cm long peduncles; bracts large, sessile, entire, glabrous, often ciliated or villous on both surfaces, cucullate, suborbicular or reniform, partly enclosing the flower. Petals 2-3 x 1.5-2.5 cm, obtuse. Female flowers yellow, on c. 2.5 cm long, ebracteate or minutely bracteate peduncles; calyx lobes linear-lanceolate, 5-6 mm long, villous; corolla similar to male flowers. Ovary ovoid, covered with long and soft papillae. Fruit ovoid or ellipsoid, 3-5 cm long, 2-3.5 cm across, yellow when mature, densely covered with soft spines, shortly beaked (rostrate) at apex. Seeds somewhat compressed, 6-7 x 5-6 mm, irregularly corrugated.