Woody vine; stem 1.5-2 cm diam., bark very thick and fissured; branchlets rather thick, 3-4 mm diam., indument caducous; pseudostipules lacking. Leaves: petiole thick, twining, 5-7 cm long; blade chartaceous, widely triangular, 11-16 x 15-20 cm, glabrous and shining above, greyish and pubescent beneath, apex acute to slightly acuminate, base slightly cordate; lateral veins marginal at base. Inflorescence cauliflorous, a dense cluster of 1-2 cm long racemes, each bearing ± 5 flowers with small scaly bracts; pedicels thin, 3-3.5 cm long, excluding the ovary. Flowers: ovary 2-2.5 cm long; perianth whitish, glabrous, outside with protruding violet brown veins; utricle ovoid, 2-3 x 1.5 cm, with a cup-shaped, annular, 1 mm wide appendage at base; tube 2 x 0.5 cm; limb suborbicular, surrounding the throat except for a ventral sinus, 5-6 x 4-5 cm, apex acute, inside brown with golden speckles near the margin, the colour fading to yellow at middle, throat yellow. Fruit ca. 6 cm long, external wall thin, chartaceous.