Hemiepiphytic, rarely terrestrial; appressed-climbing or scandent; internodes short, obscured by cataphyll fibers and roots, 1–5.5 cm x 0.4–3.5 cm, longer than broad, drying medium brown with flaky epidermis; roots several per node, drying light to medium brown; cataphylls to 12 cm, sharply 1- to 2- ribbed near apex, flattened on one side, pale green, drying medium tan or pale brown, bases persisting somewhat intact at upper nodes. LEAVES spreading; petioles firm, 1.5–11 cm x 5–10 mm (dry), terete, broadly rounded adaxially, narrowly rounded abaxiallly,
medium green, matte, drying dull, medium olive-green; blades upright to spreading, clustering at the top of the stem, subcoriaceous, oblong- obovate, acuminate at apex, narrowly rounded at base, 24.5–78 x 5.5–21.5 cm, (3.1–)3.3–3.9(–4.4)x longer than wide, (4.2–)6.6–11.8(–25)x longer than petiole, broadest at or above middle, margins rounded in distal half, concave in proximal half, adaxial surface semiglossy, dark green, drying dull and dark olivegreen, abaxial surface matte, paler than adaxially, drying glossy and reddish brown; midrib broadly convex at base to narrowly sunken at apex, marginally discolored, drying darker than blade adaxially, bluntly angular and drying darker than blade abaxially; primary lateral veins 20 to 29 per side, 5–23 mm apart, spreading from midrib at 50º–60º angles, slightly downturned at midrib, proceeding straight out to within 1.5 cm of margin, then curving sharply toward apex, sunken adaxially, raised abaxially, drying concolorous or darker than blade adaxially, darker than blade abaxially; minor veins and minute cross veins clearly visible abaxially, departing from both midrib and primary lateral veins, drying obscure adaxially, darker than blade abaxially, with many, often interrupted, secretory canals clearly visible abaxially. INFLORESCENCE erect, solitary; peduncle 1–4 cm x 4–8 mm (dry), shorter than petiole, drying medium brown; spathe long-tapered, 12–18 cm, medium green, not constricted; spathe blade 6.5– 11 cm, white inside; spathe tube 4–7 cm, dark maroon inside, drying dull medium brown; spadix sessile, 10–14 cm, white; pistillate portion 1.5–4 cm, slightly ellipsoid, to 1.1 cm diam. at widest point; staminate portion oblong, 5–9 cm, to 1.3 cm diam. near middle (dry), narrower than pistillate portion; sterile staminate portion not apparent; pistils ca. 1.3 x 0.8 mm; ovary 4- to 5-locular, ovules with axile placentation, 20 to 30 per locule. INFRUCTESCENCE unknown. JUVENILE PLANTS creeping, internodes 1–4 cm, 4 mm diam.
The species is a member of subgenus Philodendron, section Philodendron, subsection Canniphyllum (Schott) Mayo and is characterized by its hemiepiphytic habit, short internodes obscured by cataphyll bases, and leaves that cluster at the top of the stem. It also has rather large leaf blades with a distinctive oblanceolate shape for which it is named. The leaf blades are also distinctive in showing obvious secretory canals below when dry and in being held erect or spreading on very short petioles, and the inflorescences are long, tapered, green and maroon within the spathe tube. One collection, Cuatrecasas 16406, noted that the spadix had an intense, unpleasant odor.