Appressed-climbing, probably few-branched, epiphytic vine, climbing to 2.5 (-4) m on tree trunks (Croat 56511 reported as "terrestrial''), the apices at least potentially pendent. Internodes 1.1-8.0 cm long, 0,2-0.7 cm wide, dark green, matte to semiglossy, weakly and obtusely sulcate on one side, drying green and ± smooth or (usually) finely striate; roots present at distal nodes, to ca. 1.0 mm in diameter, sometimes terminating in a small, hairy, globose gall. LEAVES: Petiole (8.3-) 11.8-16.6 (-18.5) cm long, P/L=(0.38-) 0.49-0.76 (-0.81), extensively sheathed, the sheath involute to erect or spreading-erect, the free portion prolonged by 0.05- 0.30 cm; unsheathed portion of petiole obsolete or to 1.2 (-1.5) cm long. Lamina (14.3-) 18.2-28.8 (-33.6) cm long, (4.2-) 4.7-7.6 (-9.2) cm wide, L/W=(2.70-) 2.98-4.45, IQI= (3-) 5-10 (-11), thinly coriaceous, semiglossy and subvelvety above, matte to semiglossy below, slightly bicolored, narrowly elliptical to lanceolate or oblanceolate (juvenile leaves may be ovate) (broadest below to above the middle), gradually to abruptly long- or short-acuminate apically [the acumen ca. (1.0-) 1.5-2.4 cm long], broadly (or rarely) ± narrowly cuneate to rounded basally (juvenile leaves rarely subcordate to truncate); midrib sunken above, narrowly convex below; primary lateral veins often not well defined, ca. 9-13 per side, 0.2- 3.4 cm apart, weakly sunken above, convex below and darker than surface; minor veins obscurely to moderately visible below; abiaxial laminar surface drying uniformly and ± densely granular or (usually) low-granular, with the reticulate veins evident only distally and marginally; white stitching lacking or occasional; resin canals sometimes visible, especially flanking principal veins; adaxial surface similar, but may be virtually smooth or, rarely (Croat & Watt 70606), somewhat alveolate; white stitching and resin canals not evident. INFLORESCENCES solitary; cataphylls rarely observed, to at least 7.0 cm long and 0.3 cm wide, linear-lanceolate, sharply 2-keeled dorsally; peduncle (1.0-) 1.5-2.2 cm long, P/S=ca. 0.21-0.31; spathe at anthesis 7.1-12.2 cm long, 1.5-2.1 cm wide, externally variously described as "green" (Bunting 2436), "pale green to cream-colored'' (Zarucchi & Betancur 6494), "amarillo claro" (Callejas 7175), "cream'' (Madison 3881) or "blanca'' (bení- tez de Rojas 1241); spathe drying uniformly and densely granular and sometimes white-lineate externally and longitudinally pluricostate, apparently with resin canals, internally densely and uniformly granular, with stitching and reticulate venation evident and longitudinal secretory striations in basal 3/4; acumen of spathe 0.2-1.1 cm long. Stipe of spadix 0.3-0.8 cm long; spadix 6.5-ca. 9.2 cm long, the fertile male portion 0.7-1.3 cm wide, cream or white; sterile male zone 0.35-0.40 cm long; fertile female portion of spadix 2.4-3.2 cm long, F/S=ca. 0.34-0.44, 0.7-0.9 cm wide, green (Callejas 7175); fertile male flowers 1.3-1.7 mm long, 0.5-1.4 mm wide, irregularly polygonal, columnar to somewhat obpyramidal; sterile male flowers 1.60-1.65 mm long, 0.95-2. 10 mm wide, anvil-shaped; female flowers 1.4-2.7 mm long, 0.75-1.00 mm wide, the stylar canals ca. 3-4. INFRUCTESCENCES: Ripe fruits unknown. Seeds unknown.
Scandent hemiepiphyte to 2.5(-4) m; internodes 0-) 1.5-6 (-8) cm long; 5-7 mm diam., moderately smooth, drying green and smooth, striate, matte, bearing a few short roots on the flowering branches; petiole sheathing stems, 6-19 cm long (averaging 11.7 cm), 0.5-0.75 times as long as blades, sheathed throughout or nearly so, the free portion to 1.5 cm long; blades narrowly oblong-elliptic, to oblong-oblanceolate, 12-25 (-34) cm long, 4.3-6.5 (-9) cm wide (averaging 18.3 x 5.8), 2.4-3.7(-4) times longer than broad, 0.6-1.9(-2.6) times longer than the petioles, narrowly acuminate at apex, acute at base, drying green; midrib sunken above, narrowly raised below; primary lateral veins not well defined, (7-)9-13 pairs, obscure above, weakly visible on lower surface upon drying; interprimary veins about as conspicuous as the primary lateral veins; minor veins weakly visible, drying weakly wrinkled; margins drying minutely revolute. INFLORESCENCE solitary, drying reddish brown; peduncle 1-2.2 cm long, less than 3 mm diam.; spathe tube oblong-elliptic, to 1.7 cm diam. (dried); spathe blade white; pistillate spadix 1.4-3.5 cm long, ca. 1.5 cm diam.; stigmas drying conspicuously bowl-shaped, brown, 0.7-0.9 mm diam., staminate spadix ca. ca. 3.5 cm long; berries not seen.
Philodendron beniteziae ranges from Colombia (Antioquia, Choco, Narifio, Santander, Valle del Cauca), Ecuador (Carchi, Cotopaxi, Pichincha) to Venezuela (Tachira), at elevations of 1,600-2,060 m, in Premontane rain forest and Premontane wetforest.