Stem thick, up to 1.3 m long, internodes moderately long. LEAVES: Petiole terete, sappy, shortly sheathed at base, up to 50 cm long, 1.5 cm thick in the lower part; Blade thinly coriaceous, broadly ovate in outline, with a strongly open sinus in adult plants, 40-60 cm long, 30-40 cm wide, pinnatipartite, 8-16 partitions on each side, the middle one 25 cm long and 2.5-3 cm wide, the lower and upper one much shorter, almost all linear-acute, apex slightly falcate, the middle and upper ones separated by a narrow sinus, lower ones more or less larger, lowermost sinuses more or less gradually much shorter; Primary lateral veins rather robust, the lowermost partition with 4-6 joined together into posterior ribs. INFLORESCENCE: Peduncle 3-4 cm long. Spathe green inside brown-purple, oblong-lanceolate, apiculate, slightly constricted halfway, 7-9 cm long, 2.6 cm wide. Spadix somewhat shorter than spathe, female zone cylindric, 4 cm long, 5 mm thick, male zone 4.5 cm long, obtuse. Pistils oblong-cylindric, 5-6-locular, 1.5 mm long, stigma somewhat multi-lobed, locules with few ovules near the base. Male flowers usually tetrandrous.