Stem scandent, terete, robust, upper internodes 3-5 cm long, 1-1.4 cm thick. LEAVES: Petiole semiterete, 10-17 cm long, 1-1.4 cm thick; blade rigid, rather thickly coriaceous, linear-oblong or lanceolate-oblong, apex shortly acuminate, base rounded or subcuneate, 25-40 cm long, 6-10 cm wide, numerous lateral veins all subequal, parallel, prominulous, usually emerging from the midrib at an obtuse angle, arcuate ascending to near the margin and joining together; the midrib broad in the lower part gradually disappearing. INFLORESCENCE: Peduncle moderately robust, 5-8 cm long, 7-8 mm thick. Spathe internally blood-red, oblong, apex minutely acuminate, barely constricted halfway or somewhat below, 15-18 cm long, 5-6 cm wide. Spadix subsessile narrowly cylindric, gradually attenuating upwards, subacute, 13-16 cm long, 1-1.3 cm thick; female zone 3-4 times shorter than the male zone. Male flowers usually triandrous. Pistil broadly ovoid, stigma sessile, cushion-shaped, 6-8-locular, several ovules borne at the base of each locule.