Plants monoecious. Corm up to 13 cm broad, globose-depressed. Petiole mottled black, 30-45 cm long. Leaf pedate, 7-11 lobed; lobes elliptic-lanceolate, 6-23 x 1.4-7 cm. Spathe 32-44 cm long, tube ovoid, margins connate, much shorter than the limb, greenish, mottled purplish-black inside. Peduncle 1.5-3.5 cm long. Spadix shorter than the spathe, appendage pale green, stout, 14-18 (-21) cm long, obtuse. Male zone 1-13 cm long. Neuter zone 1-1.2 cm long; neuter organs clavate, 4-5 mm long, yellow. Female zone 1.5-2 cm long. Ovary obovoid. Stigma sessile. Berries red. Seed ± ovoid, c. 1.8 mm broad.