Herb, stem of juvenile plant scandent, eventually the uppermost internodes abbreviated and thickened, stem in adult part up to 50 cm long, and 2.5 cm in diameter, 8-10 leaves towards the apex. Cataphyll soon marcescent, slowly breaking up. LEAVES: Petiole up to 41-50 cm long and ca. 1.4 cm thick, subterete, ventrally broadly canaliculate, sheathed in the lower part for 7 cm; geniculum prominent, 4-6 cm long, similar in shape to the petiole but laterally compressed, 1.4 cm wide and 1.7 cm thick when seen from the side. Leaf blade coriaceous but brittle, narrowly obovate or oblong, towards the base broadly obtuse or truncate, acuminate towards the apex, up to 79 cm long and 19-21 cm wide, margin strongly undulate; ca. 8 primary lateral veins on each side, with one secondary vein between each pair, erect-spreading, arcuate towards the margin, minor veins parallel, bright ('laete') green, barely glossy, midrib angular-canaliculate, primary and secondary lateral veins sulcate, abaxially pale green, midrib robust, parabolic in transverse section. INFLORESCENCE: Peduncle very pale green, ca. 7 cm long and 1.2 cm thick, marked with raised, white striations near apex. Spathe 16-17 cm long; tube ovoid, ca. 6 cm long and 4.5 cm in diameter, narrowing to 2.7 cm in diameter in the upper part, externally and internally pale green; limb 10 cm long, acute at apex, pale green externally and densely punctate with very pale green. Spadix up to 13.5 cm long, female zone 3.3 cm long at the front, and 2.4 cm long at the back, 2 cm in diameter; sterile male zone 4 cm long and 1.7-1.8 cm in diameter, fertile male zone 6.3 cm long, 1.5 cm in diameter near the base, attenuating gradually upwards, obtuse at apex. Pistillate flowers: ovary 7-locular, many ovules in each locule, positioned at the top.