Epipetric vine; internodes 2-6 cm long, 1-1.8 cm diam, green soon turning gray-green, somewhat flattened on one side, drying light brown and deeply fissured longitudinally with sharp ridges, the epidermis thin, often cracking loose; cataphylls green, 14-17 cm long, sharply 2-ribbed, soon deciduous. LEAVES with petioles 12-22 cm long, 1-1.5 cm diam., spongy, terete to obtusely flattened adaxially or sometimes with a faint, medial sulcus (Liesner & Cuariglia 11526), drying blackened with an even darker black ring around apex of petiole; blades moderately thin, ovate-elliptic to elliptic-oblanceolate, 24-45 cm long, 8-14 cm wide, broadest at or above the.middle, drying usually blackened, long-acuminate at apex, gradually narrowed in the lower one-fourth and subcordate at the base, the lobes rounded, extending 1-3 cm below the apex of the sinus, the latter acutely to obtusely V-shaped; both surfaces semi-glossy, dark green above, slightly paler beneath; midrib broadly convex above, more prominently raised beneath; primary lateral veins 8-10 pairs, arising at 55-65° angle, almost straight to the margins, sunken above, raised beneath; minor veins distinct beneath, all major veins usually drying black, darker than the surface. INFLORESCENCES 1-2 per axil; peduncles 7-13 cm long, slightly shorter than or longer than the spathe; spathe 12.5-14 cm long, greenish (all seen post-anthesis), not abruptly constricted, but narrowing gradually aboutmidway; spathe tube ca. 6 cm long, oblong-ellipsoid, spathe blade abruptly acuminate; spadix 0.5 cm shorter than the spathe; pistillate portion ca. 6-7 cm long, 1.2 cm diam. at anthesis, to 7 cm long, 3.5 cm diam. in fruit; pistils (dried) 1.5 mm long, the stigma button-shaped with small pit-like depressions in a small circle at the center, subtended by an irregularly shaped, 4-5 lobed apron 0.7-1.4 mm diam.; sterile staminate section 4-5 mm long, ca. 5 mm wide; fertile staminate portion more or less cylindroid, gradually tapered to its broadest point about midway on the spadix, (3)5-7 cm long, ca. 9 mm diam., bluntly tapered to the apex. INFRUCTESCENCE not seen.