Stem scandent, terete, robust, upper internodes 6-8 cm long, 1-1.2 cm thick. Cataphyll linear-lanceolate, soon deciduous. LEAVES: Petiole somewhat flattened on the upper surface, with a short, rather wide, persistent coriaceous sheath. 15-22 cm long. Blade thinly coriaceous, ovate-cordate, 28-32 cm long, up to 23 cm wide; posterior lobes 9-12 cm long, semi-ovate, rounded-obtuse, separated by a very obtuse wide sinus; anterior lobe 23-25 cm long, ovate, apex shortly oblique, cuspidate-acuminate. 2-3 primary lateral veins from the posterior lobe, these shortly joined together, posterior ribs denuded for 2 cm in the sinus; interlobe vein spreading; 5-6 primary lateral veins in the anterior lobe, remote, emerging from the midrib at ca. 50-60º angle, ascending arcuately towards the margin, the midrib rather robust in the lower part, strongly attenuating upwards. INFLORESCENCE: Peduncle short, terete, rather robust, 4 cm long. Spathe oblong, 8-9 cm long, somewhat constricted halfway, apiculate, convolute, 1-1.2 cm in diameter. Spadix: Female zone cylindric, 3 cm long, 8 mm thick, male zone subclavate, acute, almost 5 cm long, 6 mm thick, somewhat narrowing towards the base and apex. Pistil subovoid, obtuse at the top, stigma slightly rounded, barely raised.