Stem terete, robust, scandent high up, eventually almost 10 cm thick, internodes rather long. LEAVES: Petiole terete, sappy, up to 60 cm long, 2 cm thick in the lower part, attenuating upwards, often marked with pale green spots, sheathed at the base for 3-5 cm; Blade thinly coriaceous, ovate or oblong-ovate in outline, with a strongly open sinus at the base, 40-70 cm long, 30-50 cm wide, pinnatipartite, 6-9 linear divisions on each side, apex acute, usually somewhat falcate, middle divisions 20-25 cm long, 3-4 cm wide, upper divisions smaller, middle and upper divisions separated by narrow sinuses, lower divisions closer together; one strong primary lateral vein in each division, the lowermost with 3-4 veins joined into a short posterior rib which is barely denuded. INFLORESCENCE: Peduncle terete, 6-8 cm long, 1.5-1.8 cm thick, somewhat attenuate towards the base. Spathe green externally or eventually greenish-pink, internally dirty dark purple, oblong-lanceolate, slightly constricted halfway or somewhat above, 15-17 cm long, convolute, ca. 3 cm in diameter. Spadix shortly obliquely stipitate, somewhat shorter than the spathe, female zone cylindric, 6-6.5 cm long, 1.5 cm thick, male zone equal in length to the female zone, attenuating somewhat upwards, finally rather obtuse. Pistil subcylindroid somewhat attenuate towards the apex, 5-6-locular, ca. 2 mm long and 1.5 mm wide, stigma more rounded, slightly lobed. Male flowers 2-3-androus.