Stem robust, scandent up to 4 m high, 4-5 cm thick in the lower part, upper internodes short. LEAVES: Petiole semi-terete, longitudinally and deeply canaliculate on the entire upper surface, 40-50 cm long, 1 cm thick at the base, shortly and narrowly sheathed in the lower part. Blade rather thick, coriaceous, broadly ovate-cordate, 30-35 cm long and almost equally wide; posterior lobes oblique, semi-ovate, separated by a wide sinus; anterior lobe semi-ovate, apex acute, almost 2 times longer than posterior lobes; 5 primary lateral veins of the posterior lobes on both sides, joined together at the base into short posterior ribs, not denuded in the sinus, one interlobe vein and 2 veins of the anterior lobe borne from the base, the remaining 3-4 veins spread from the midrib at and obtuse angle, with a distance of 3-5 cm between each other, all rather robust, curving upwards near the margin. INFLORESCENCE: Peduncle 1-2 cm long. Spathe green externally, whitish internally, ca. 6 cm long, convolute. Spadix: female zone cylindric, 3 cm long, 6-7 mm thick; male zone conoid, obtuse, equal in length to the female zone, 5-6 mm thick. Pistils ovoid-conoid, ca. 1.5 mm long, stigma small, orbicular, 4-5 locular, locules 1-2-ovulate.