Herb, long-scandent, up to 15 m long adhering to tree trunks, roots pendent. Stem tough, dark green, blended with purple near the apex, internodes 8-12 cm long and 1-1.5 cm thick. Cataphyll 9-9.5 cm long, pale green blended with purple soon pink to purplish, then marcescent, intense brownish and persistent in position. LEAVES: Petiole firm, sub-terete, slightly flattened ventrally, 13-24.5 cm long and 0,3-0,5 cm thick, pale green, blended purple upwards or pale wine-coloured in the distal 2 cm. Leaf blade thinly sub-coriaceous, barely brittle, smooth, oblong-elliptic or narrowly obovate, sub-cordate at the base (emarginate), apex obtuse with recurved acumen, 21.5-33 cm long and 7.5-10.5 cm wide, undulate on both sides of the midrib, in a series of ca. 14 regular concave depressions, the shapes itself not reaching as far as the margin, the margin itself sub-flat although revolute; adaxially glossy, bright ('laete') green, midrib moderately convex, 0.4 cm wide, 5-6 primary lateral veins on both sides, patent, barely distinguishable; abaxially rather glossy, pale green (almost silver-green), midrib angular, ivory-white, occasionally suffused with pink, and marked near the base with few elliptic wine-coloured spots. INFLORESCENCES solitary on pendent branches. Peduncle coloured in the same way as the petiole, pink at the apex, 6-6.5 cm long. Spathe (post anthesis and unopened) narrowly conical, narrowed towards the base, ca. 9 cm long, 1.6 cm wide below, not constricted between the tube and the blade; externally green or greenish-white and pink margined, marked below with 4 pink longitudinal stripes; internally cherry red-wine-coloured in the lower half, greenish above. Spadix somewhat shorter than the spathe, ca. 7 cm long; female zone 3.6 cm long and 1.3 cm wide. Pistillate flowers: ovary 2-locular, many ovules in each locule, superposed.
The species is distinguished by its high climbing habit, long, slender internodes, terete petioles, the ovate-oblong blades with scarcely any development of primary lateral veins and with a sub-cordate base. The inflorescence is creamy, suffused with lilac outside on the tube and purple-magenta inside on the tube. Herbarium material is perhaps most easily confused with P. ptarianum, but the latter differs in having short internodes, a creeping habit, sulcate petioles and waxy blades.
Known until recently only from Venezuela, is known from Brazil (Roraima), Colombia (Vaupes) and Peru (Loreto). In Venezuela, it is known from southern Bolivar (vicinity of Santa Elena and Icabaru as well as Cano Pablo, a tributary of Rio Caura) and in Amazonas (Cerro Arauicaua, vicinity of Pimichín and along the Rio Cataniapo).