Herbaceous climber to 4 m, growing from a tuberous rootstock; glabrous. Leaves pale- or greyish-green, often punctate beneath, simple, broadly ovate to ± hastate, base cordate to truncate, apex obtuse to acute, up to 2 mm subapical mucronate, 1,5-10 (-14) X' 1,5-10 (-13) cm, 3-7-(sub)plinerved; margin entire; petiole (0,5-5 (-10) cm. Gland(s) at blade-base 1 or 2, contiguous, situated on the not- or shortly-peltate, sometimes 2-lobed blade-base; blade-glands 0-2 (-4), often conspicuous, (sub)marginal or near the top; leaves of juvenile specimens with peltate base, without glands. Stipules narrowly triangular, acute, 1,5-2 mm. Inflorescences peduncled for 0,5-4 (-11) cm, up to 12-flowered in S, 1-3-flowered in ?; tendril (0 or) 1, 1-5 cm; sterile tendrils up to 12 cm. Male flowers tubiform to infundibuliform, including the 2-6 mm long stipe (13-) 15-30 cm; hypanthium cup-shaped, tapering, 2-3 mm; calyx-tube (5-) 7-15 x (3-) 4-5 mm, lobes ovate to elliptic, obtuse, 4-7 mm, densely fimbriate; petals linear-lanceolate, 5-7 (-9) mm,