Epiphytic vines appressed-climbing on tree trunks or over shrubs in forest understood, usually fertile 1.5-3.5 m above ground. Internodes 1.6-11.4 cm long, (0.2-) 0.4-1.3 (-2.0) cm wide, dark green to gray-green, matte or velvety to glaucous or weakly glossy, obtusely sulcate or flattened on one side, drying yellow- green to blue-green and finely striate; roots often present at distal nodes, to ca. 2.0 mm in diameter, sometimes with small, globular nodules. LEAVES: Petiole (12.9-) 13.5-42.2 cm long, P/L= (0.40-) 0.45-0.83 (-0.89), matte, striate-roughened proximally, sheathed (84-) 88-97 (-98)%, the sheath erect to involute, ± scarious-margined, adnate distally or with the free portion prolonged to ca. 2.5 (-3.0) mm; unsheathed portion of petiole 0.3-4.0 cm long, D-shaped, sulcate above with the margins obtuse to subacute, thickened and subgeniculate distally. Lamina (25.2-) 27.0-56.2 cm long, (5.7-) 10.0-23.2 (-25.2) cm wide, L/W= (1.10-) 1.78-4.35 (-4.68), IQI= 1-16 (-19), thinly coriaceous to coriaceous, sometimes ± chartaceous, matte or velvety to glossy above, matte to weakly glossy below, moderately to prominently bicolored, narrowly to broadly lanceolate or oblanceolate to rarely elliptical or obovate, acute to gradually or abruptly acuminate to long-acuminate apically [the acumen 1.1-2.3 (-2.9) cm long], narrowly or broadly cuneate to rounded or truncate basally (usually subcordulate at petiole apex); midrib sunken above, narrowly convex and sometimes slightly paler below; primary lateral veins (10-) 12-30 or more per side (often with ± indistinguishable interprimaries), 0.6-4.7 cm apart, sunken above, convex and darker below; minor veins obscurely to moderately visible below, somewhat darker; abaxial laminar surface drying practically smooth to obscurely or sparingly to densely and uniformly granular (with the granules sometimes concentrated along the veins); reticulate veins obvious only proximally or peripherally (especially prominent in Ecuadorean material); white stitching not evident; resin canals rarely visible distally (especially subsp. rhodoaxis); adaxial surface practically smooth or obscurely to densely low-granular or rugulate (the granules sometimes tending to be concentrated along veins) , sometimes also subalveolate; reticulate veins obscure to evident throughout; white stitching and resin canals not evident. INFLORESCENCES typically paired, occasionally solitary, rarely in 3's; cataphylls of regular occurrence, (5.4-) 10.6-30.9+ cm long, 0.3-1.9 (-2.6) cm wide, greenish white, narrowly to broadly lanceolate, sharply 2-keeled; peduncle 3.7-11.6 cm long, P/S=0.34-0.82 (-0.89), compressed or bluntly angled, coarsely pale-striate distally; spathe at anthesis 10.5-17.8 cm long, (1.6-) 2.0-3.4 cm wide, externally weakly glossy to semiglossy, green below (paler toward margins), cream to greenish yellow distally (in fruit may become uniformly lemon- yellow), internally ± uniformly greenish cream to cream or yellowish green; spathe drying moderately to densely and evenly granular externally, obscurely to evidently short-white-lineate with some resin canals often visible, internally virtually smooth to sparingly or densely and evenly granular, with longitudinal secretory striations 1/2 to 9/10 to apex; acumen of spathe 1.1-2.8 cm long. Stipe of spadix 0.25-2.00 cm long, at least partly adnate to spathe; spadix 8.7-15.3 cm long, the fertile male portion (0.6-) 0.8-1.5 cm wide, cream-white, curved forward at ca. 45º angle at female receptivity; apical sterile male zone (when present) to 2.0-3.7 cm long; intermediate sterile male zone 0.4-1.3 cm long; female portion of spadix 2.2-5.3 cm long (to 6.2+ cm in fruit) , F/S=0.19-0.38 (-0.43), 0.8-1.4 (-1.9) cm wide (to 2.9+ cm in fruit) , pale yellowish green; fertile male flowers 1,0-2.1 mm long, 0.7- 2.0 (-2.6) mm wide, irregularly polygonal, columnar; apical sterile male flowers (subsP. lewisii) 1.2-1.5 mm long, 0.8-4.3 mm wide, lamellar; intermediate sterile male flowers 1.4-2.1 mm long, 1.0-2,9 mm wide, narrowly to broadly anvil- shaped; female flowers 1.6-3.2 mm long, 0.7-1.5 (-1.7) mm wide, the stylar canals 3-5. INFRUCTESCENCES: Ripe fruits (subsp. lewisii) translucent-whitish. Seeds (subsp. lewisii) 0.4-0.6 mm in diameter, ca. 0.2 mm thick, variously described as pinkish, magenta, red, reddish, or purple (conferring this color to translucent fruits), C-shaped to cochleate, finely and minutely striate with the striae not or very minutely can- cellate, drying dark brown and semiglossy.