Appressed-climbing hemiepiphyte to -3 m above ground, rarely terrestrial; stems to 1 m long; internodes short, (2)4-8 cm long, (0.6)3-5 cm diam.; cataphylls 21-44 cm long, faintly to sharply 2-ribbed to sharply D-shaped, green or green-tinged weakly with red or purple, drying brown with distinct striations, persisting intact to semi-intact and dilacerating into a net of fine fibers with mucilage (with thin patches of epidermis), epidermis brown to rusty-brown; petioles terete to obtusely flattened adaxially, 17-60(100) cm long (av. 35.7 cm), 0.54-1.69 times longer than blade (av. 1.08 times longer), 0.6-1.2 cm diam. midway, firm, semi-glossy, gray-green to medium and dark green, sometimes dark green with darker green lines; geniculum 1.3-3 cm long, sometimes slightly darker, scurfy, slightly broader than petioles; sheath short or almost absent, up to 3 cm long; leaf blades lanceolate (probably-pre-adult), narrowly ovate-triangular to broadly ovate and sometimes truncate, 17-49(68) cm long (av. 40 cm), 7.6-36 cm wide (av. 19 cm), and 1.2-3.9 times longer than wide (av. 2.4 times), acuminate at apex, subcoriaceous to coriaceous, weakly glossy to glossy, dark green and matte, slightly bicolorous above, much paler and semiglossy below, anterior lobe 37-62 cm long, margins usually broadly convex, sometimes straight, occasionally concave; posterior lobes 9-20 cm long; midrib flat, slightly paler, concolorous, and broadly convex on upper surface, raised and paler on lower surface; primary lateral veins 6 to 10 per side, 8 to 20 pairs, arising at sharp angle then spreading at 45-60° angle from midrib, gently curving toward apex, sunken above, raised and darker than surface below; minor veins obscure above, distinct or rarely indistinct below; cross-veins drying distinct; basal veins 2 to 5 per side, 1st pair free to base, 2nd & 3rd pairs often coalesced 1-2 cm; posterior rib short and straight, never naked along sinus; sinus (when present) parabolic to arcuate or subhippocrepiform. INFLORESCENCES up to 8 per axil; peduncles (3.0)8.0-15.5 cm long (av. 10.1 cm), 7-10 mm (drying 3-8 mm) diam., terete to weakly flattened, conspicuously striate, erect to somewhat spreading, green with paler streaks, white at base, tinged red; spathe 8-14.5(17) cm long, tapering toward apex with spathe sometimes turned upward from peduncle; spathe tube 3-5.3 cm long, 2-3.6 cm diam., 'green to pale green with white streaks outside, whitish to pale green or light red inside with translucent resin canals, these eventually with pale yellow resin in lower 2/3 of tube; spathe blade white to yellowish white, sometimes bent backward about midway at anthesis (Croat 49605); spadix 7.5-13 cm long, female portion 1.9-2.2 cm long, 1.2-1.4 cm diam., greenish white to white or pale yellow-green; male portion creamy-white to white, 3.5-8.5 -cm long, 1 cm diam. 1 cm above base, 7 mm diam. 1 cm below tip; sterile male portion ca. 1 cm long, 1.4-1.6 cm diam.; sterile male flowers 1.75 mm long, 1.75 mm diam., fertile male flowers 1.5-2.4 mm long, 1.3-1.5 mm diam., narrowed toward base, stamens 3 to 5 per flower; pistils 1.5-3 mm long, 1-2 mm diam., 4- to 6-locular, drying dark tan; style 0.6-0.8 mm long, 1.25 mm diam.; stigma depressed-globular, 1-1.2 mm high;, style irregularly circular in outline with a central indentation and usually 4 to 6 indentations in a circle around a central pore (thebe corresponding to the usual number of locules), drying shield-like, ca. 2 mm diam., extending slightly over margin of ovary; locules 4 to 7 per ovary, 2.1 mm long; ovules hemi-anatro-pous, ca. 25 per locule, 0.4-0.5 mm long; axile placentation, biseriate: funicle 0.3-0.4 mm long. INFRUCTESCENCE with berry yellowish to orang-ish or greenish white, seeds 1 mm long, 0.5 mm wide, with 8 to 10 longitudinal striations (ridges), narrowing near chalazal end, drying tan.
Philodendron asplundii is restricted to the Amazon basin and ranges from southern Venezuela (Amazonas) and French Guiana to Brazil (Acre, Amazohas), Colombia (Putumayo, Amazonas, Caqueta), Ecuador (Sucumbios, Napo, Pastaza, Morona-Santiago), and Peru (Amazonas, Loreto, San Martin, Huanuco, Pasco).