A climber, glabrous in all its parts. Stem 20 ft. long; branchlets slender, terete. Leaves ovate- or triangular-cordate, shortly and abruptly acuminate, with a wide rounded basal sinus, 6–8 in. long, 5–6 in. wide, entire, membranous, paler below; primary nerves 5–11, arising from the base of the leaf, arcuate; petiole 6 in. long. Flowers solitary, greenish with red-purple ribs outside, brownish and yellow mottled inside, very large; utricle 8 in. long, 2 1/2–3 in. wide, subcylindrical, sharply curved near and gibbous at one side of the top, 6-ribbed, furnished inside with soft hairs; tube 4–6 in. long, broadly funnel-shaped, many-ribbed; limb 9 in. in diam., 5–6 in. long, shortly campanulate, strongly ribbed, with a membranous curtain 6 lin. wide from its throat; lobes 3, equal, broadly and shortly triangular, suddenly contracted into tails 1–2 in. long. Gynostemium subsessile, 1 1/2 in. long, hollow. Anthers about 24 narrowly linear, 1 in. long. Style-arms about 12, bifid, stigmatic at the apex.