Stem scandent, upper internodes up to 10 cm long, 1.2-1.5 cm thick. LEAVES: Petiole slightly canaliculate anteriorly (antice) at the base, shortly sheathed at the base, 40-50 cm long; blade sub-coriaceous, elongate-cordate-sagittate, 30-40 cm long 14-20 cm wide in the lower part; posterior lobes oblong, obtuse, separated by an obtuse sinus; anterior lobe oblong acuminate, 4-4.5 times longer than the posterior lobes; midrib thick in the lower part, attenuating upwards; primary lateral veins numerous, robust; 6-7 veins posterior lobes, not or only very shortly joined into a posterior rib, [directed] upwards near the margin, 14-15 primary lateral veins of the anterior lobe spreading on each side, from these robust secondary veins emerge. INFLORESCENCE: Peduncles 8-10 cm long, several in one inflorescence. Spathe oblong acute, slightly constricted halfway, measuring ca. 12 cm. Spadix subsessile; female zone cylindroid, 3-3.5 cm long, 1 cm thick; male zone oblong, obtuse, 6-7 cm long, sterile base thicker than female zone, attenuating upwards. Pistils shortly ovoid, almost 2 mm long, with a small discoid stigma, 4-locular, ovules ascending from the base. Male flowers usually triandrous; stamens prismatic, thecae of the top of the stamens obovate, not touching at all.