Delicate to coarse vines or scandent vines or lianas (perhaps rarely terrestrial), climbing to at least 10 m; fertile branches drooping and usually divergent, looping upward apically. Internodes 0.2-11.8 (-18.1) cm long, 0.35-1.25 cm wide, dark green to gray-brown, weakly glossy to semiglossy, flattened on one side, drying yellowish to light brown and coarsely sulcate; roots rarely present at distal nodes. LEAVES: Petiole (3.5-) 4.8-18.8 (-24.4) cm long, P/L=(0.25-) 0.33-0.58 (-0.97), some- times weakly tuberculate proximally, extensively sheathed, the sheath erect to involute or (less commonly) horizontally splayed, free apically and prolonged to 1.1 (-2.1) cm (often well beyond base of blade); unsheathed portion of petiole 0.0-1.1 (-2.0) cm long, canaliculate above. Lamina (10.0-) 14.2-29.3 (-30.9) cm long, (2.6-) 3.1-12.3 (-18.0) cm wide, L/W=(1.16-) 1.92-5.17 (-6.40), IQI=0-7 (-15?), thinly coriaceous, semiglossy or somewhat satiny on both surfaces (or matte above), concolorous to weakly bicolored, narrowly to broadly (often deltately) lanceolate to narrowly or broadly ovate, rarely narrowly or broadly oblanceolate, oblong or elliptic (generally broadest below the middle), abruptly to (most commonly) gradually to very gradually short- to long-acuminate (rarely merely acute) apically [the acumen 0.2-1.8 (-3.1) cm long], cuneate to truncate or, more usually, rounded and often circulate (rarely cordate with the sinus to 1.1 cm deep) or occasionally articulate or subsagittate basally; midrib sunken above, convex and paler below; primary lateral veins (6-) 8-12 (-15) per side, 0.1-3.6 (-5.5) cm apart, weakly sunken above, weakly convex below; minor veins obscure to weakly visible; abaxial laminar surface drying smooth to moderately granular, with oblique cross-veins especially toward the base; white stitching scattered to abundant; resin canals prominent, interrupted; adaxial surface relatively featureless, occasionally resembling abaxial surface but usually with reticulate venation, white stitching and resin canals less obvious or not evident. INFLORESCENCES always solitary; cataphylls very infrequent, when present 1 (-2) per inflorescence, 7.9-11.3 cm long, 0.5-1.7 cm wide, lanceolate with an obscure median costa; peduncle 0.6-1.5 (-2.1) cm long, P/S=0.08-0.25, mostly concealed in leaf sheath; spathe at anthesis 5.8-13.8 (-16.4) cm long (to 18.9+ cm long in fruit), 1.5-3.4 (-4.7) cm wide, externally semiglossy, green or yellowish green to cream-colored, typically palest distally, internally uniformly pale greenish or cream (rarely with basal reddish wash); spathe drying virtually smooth externally, often with white stitching, finely plicate or costate with ± prominent vertical resin canals, internally virtually smooth to (more commonly) finely and densely granular, with longitudinal secretory striations ex- tending nearly to the apex; acumen of spathe 0.1-1.4 (-2.2) cm long. Stipe of spadix 0.2-1.0 (-1.4) cm long, mostly adnate to spathe; spadix 3.6-12.4 (-14.3) cm long, the fertile male portion 0.6-1.9 cm wide, cream-colored, deflexed forward at female receptivity; sterile male zone absent or, if present, 0.4-1.2 cm long; female portion of spadix 1.5-4.0 (-5.6) cm long (to 8.7+ cm in fruit), F/S=(0.22-) 0.25- 0.58, 0.6-1.8 cm wide (to 5.5+ cm in fruit) , light green; fertile male flowers (1.0-) 1.4-2.3 mm long, 0.5-1,7 mm wide, irregularly polygonal, columnar; sterile male flowers 2.1-3.0 mm long, 0.9-2.7 (-3.5) mm wide, anvil- to narrowly mushroom- shaped; female flowers 2.0-4.3 mm long, 0.7-1.5 (-1.9) mm wide, the stylar canals (3-) 4-6 (-8) per flower. INFRUCTESCENCES: Ripe fruits variously described as green, yellow, orange, or purplish. Seeds 1.0-1.3 mm long, 0.20-0.35 mm wide, usually straight and spindled, sometimes ± curved, drying brown and glossy, finely striate with the striae minutely cancellate.