Dioecious twining vine, climbing into canopy; stems terete, smooth except for some very fine longitudinal ribs (at least when dried). Leaves alternate; petioles 8-12 cm long, +/- terete; blades ovate, acuminate, cordate at base (sinus ca 4-6 cm deep), 16-30 cm long, 11-20 cm wide, upper surface glabrous, rugose in age, the lower surface with sparse, inconspicuous, dark, plate-shaped glands; veins 9-11, conspicuous, palmate, the major veins arcuate-ascending, impressed above on older leaves, the secondary veins nearly perpendicular to primary ones, the tertiary reticulations less conspicuous, all veins minutely papillate, the secondary and tertiary veins sparsely pilose. Panicles axillary, about as long as leaves; staminate flowers solitary at nodes, sessile or with a pedicel l-2 mm long; perianth ca 1.5-2 mm long; bracts sharply acuminate, ca 1.5 mm long; pistillate flowers not seen. Capsules ca 3.5 cm long and 6 cm wide, the inner surface of the valves brown, shiny; seeds disk-shaped, ca 2 cm or more in diam, the seminiferous areas at the center. Croat 11880a, Montgomery 15.