Scandent herb. Stem up to 4 m long, 2.4 cm in diameter, internodes (2-)3-5 cm long, naked. Cataphyll 16-17.5 cm long, caducous. LEAVES: Petiole thick (swollen in juvenile plants), subterete, nevertheless rather flat adaxially near the apex, 22-31 cm long, 1.7 cm wide (halfway) sheathing part 2.2-5.8 cm long. Leaf blade flat, subcoriaceous (or rather thickly papery when dry) unequally sided, broadly ovate, 30-35 cm long, 22-29 cm wide; obliquely cordate or subcordate at the base; posterior lobes rounded, separated by a short 2-5 cm long sinus; broadly obtuse at the apex (125-130º), the apex itself abruptly acuminate (0.4-1 cm); adaxially deep green, glaucescent or semiglossy; midrib almost flat and 1.4 cm wide near the base, convex further up; primary lateral veins sulcate, 7 on both sides, emerging at an angle of ca. 70-75º; abaxially midrib broadly convex, primary lateral veins convex. INFLORESCENCES in fours or fives. Peduncle 6-10 cm long. Spathe lacking constriction, the same diameter throughout, 7-7.5 cm long, 0.7-0.8 cm in diameter; the lower half green externally, cherry red internally; the upper half both surfaces white; eventually up to 9.2 cm long, 1.1 diameter in the lower part, 0.9 cm further up. Spadix somewhat shorter than the spathe, stipitate, stipe 0.1-0.3 cm long at the back, 0.3-0.6 cm long at the front; female zone 2.1-3 x 0.65 cm; sterile male zone 0.5-0.6 x 0.45 cm; [male] fertile zone 3.3 x 0.55 cm. Pistillate flowers ovary 5-locular, locules uniovulate. Staminate flowers constantly 3-androus.
The species is recognized by its scandent habit, caducous, unribbed cataphyll, moderately spongy, more or less terete petioles, its ovate, inequi-laterally ovate, subcordate to cordate blades with a triangular sinus which is broader than deep and with the posterior rib not naked. Also characteristic are the inflorescences which occur in clusters of 4-5 per axil, have uncon-stricted spathes with the tubes green outside, maroon within and with the blades white on both surfaces.