Scandent herb. Stem… LEAVES: Petiole 39 cm long, sheathed part 6 cm long. Leaf blade papery (membranaceous when dry), outline more or less triangular, moderately unequal-sided, near halfway the margin on one side narrower, convex, the other side concave; 37.5 cm long, 17.5 cm wide (opposite petiole insertion), more or less sagittate-cordate at base; posterior lobes rounded, separated by a 5.5 cm long, broadly parabolic sinus; one lobe 7 cm long, 2.5 cm longer than the other; adaxially dark green, midrib 0.8 cm wide near the base (when dry); primary lateral costal veins ca. 12 or more on each side, at an angle of 70-80º, usually 3 strong veins in the posterior lobes, joined together into short posterior ribs, naked for 1.5-2 cm in the sinus. INFLORESCENCE solitary. Peduncle 7 cm long. Spathe 10.3 cm long, externally pale green, tube 5.5 cm long, internally from brown to red, blade whitish. Spadix equal to the spathe; the axis naked at the front for 0.5 cm; female zone 8 cm long; sterile male zone 0.7 cm long; fertile male zone 4.2 cm long (when dry). Pistillate flowers: ovaries 5-7-locular, locules 2-ovulate. Staminate flowers usually 3-2-androus.