Large scandent herb, up to 4 m long or more. Stem 10 cm thick, internodes short. Cataphyll marcescent, deciduous eventually. LEAVES: Petiole subterete in the lower part, ventrally flattened, upper part more or less semiterete, but convex ventrally, up to 1 m long or longer and 2.3 cm thick, olivaceous, rusty-red spotted in the upper third.. Blade somewhat shorter than petiole, reflexed, subcoriaceous, up to 90 cm long and 48-50 cm wide, triangular-ovate in outline, sagittate at the base, acuminate at the apex, margin undulate, pink margined, pinnatilobuled (for less than 1/3 the distance from the margin to the midrib), lobules broadly obtuse, numbering 9-10 on each side, on the outside, corresponding to the primary lateral veins. Primary lateral veins from the midrib 6-7 on each side departing at ca. 55-70º, arcuate, 3 departing from the outside of the basal ribs. The posterior lobe has 3-4 lobules on the inner side, lobes trapeziform in outline, frequently touching or overlapping, separated by a more or less rhombic sinus, 22-27 cm long; Posterior ribs naked in the sinus for ca. 5 cm. Adaxially deep green, glaucescent, midrib flat and 1.2 cm wide, posterior ribs and primary veins moderately convex and sparsely rusty-red-spotted, abaxially yellowish green, somewhat glossy, midrib strongly raised-angular and primary veins rusty-red-spotted. INFLORESCENCES at least 3. Peduncle 9 cm long, green, apical part red-wine-coloured for 1 cm. Spathe up to 19 cm long, tube ellipsoid-obovoid, 10-11 cm long and 5 cm wide, externally pale green and irregularly rusty-red marked and spotted, internally intense mauve-rusty-red, blade acuminate with a ling and recurved mucro, externally whitish and marked with rusty red, whitish inside. Spadix subequal to spathe, obtuse towards the apex, subsessile but naked for 0.5 cm at the front, 17 cm long, female zone 6 cm long and 2 cm in diam., sterile male zone 2.5 cm long and 2 cm in diam., fertile male zone 8 cm long and 1.5 cm in diam. Pistillate flowers subcylindric, ovaries 6-8 locular, 3-5 ovules in each locule, affixed near base.