Hemiepiphytic; stem appressed-climbing to 4 m high or creeping, to 30 cm long; internodes short, very thick, semiglossy, 1--4 cm long, (1.5--2)3--4(6--10) cm diam., much broader than long, medium to pale green, coarse white-ribbed at upper edge, completely hidden by cataphyll fibers, drying brown; roots several per node, to 4 mm diam., light reddish brown to dark brown with flaky lighter brown epidermis, weakly glossy; cataphylls (20)55--70 cm long, sharply 2-ribbed, sharply sulcate with acute marginal ribs, green, heavily tinged with red toward base, sometimes red throughout, drying reddish brown, with two low ribs, persisting semi-intact at upper nodes, as pale fibers at base, eventually as dark brown to reddish brown fibers; LEAVES: petioles 27--108 cm long, 9--15 mm diam., subterete to obtusely D-shaped, firm and flexible, obtusely to weakly flattened adaxially, with adaxial margins sharp to bluntly rounded, dark green, base reddish, weakly glossy, surface faintly and densely white striate to coarsely pale striate, drying dark brown; blades triangular-sagittate, moderately coriaceous to subcoriaceous, short- to long-acuminate at apex (the acumen sometimes inrolled), cordate at base, 32.5--91 cm long, 11--44 cm wide (1.34--3.28 times longer than wide), (0.58--1.05 times longer than petiole), about equal in length to petiole, broadest at or near point of petiole attachment, upper surface dark green, with velvety sheen, drying gray-green to yellow-brown above, lower surface yellow-green, semiglossy, paler, drying reddish brown below; anterior lobe 39.5--68 cm long, 22--53 cm wide (1.2--1.8 times longer than posterior lobes); posterior lobes 6.2--29.6 cm long, 10.3--26.5 cm wide, directed inward, obtuse to rounded; sinus parabolic, hippocrepiform or spathulate; midrib narrowly rounded to almost flat to weakly sunken, drying gray-brown, paler than surface above, narrow-rounded to convex, concolorous or paler than surface, drying reddish brown below; basal veins (3--4)5--8 per side, with 0--1 free to base, (1)2--3 coalesced 0.9--7.5(11.5) cm, posterior rib naked 2-4 cm, sometimes not naked but with the rib sometimes running very near the margin; primary lateral veins 7--8 per side, departing midrib at a 60--70º angle, nearly straight to the margins, obtusely sunken, concolorous or paler than surface above, prominently convex to narrowly rounded, concolorus or paler than surface below; interprimary veins many, distinct; minor veins fine, moderately distinct; "cross-veins" visible on lower surface, sometimes weakly visible above. INFLORESCENCES more or less erect, 3 per axil; peduncle 9 cm long, 8--9 mm diam., white tinged red, pale white striate toward apex, turned at 100E angle to spathe at anthesis; spathe 14.2 cm long, (1.57 times longer than peduncle), weakly constricted above the tube; spathe blade white outside, whitish, suffused maroon to about midway inside; spathe tube globose, 6 cm long, pale green, tinged red on front outside, densely short, pale streaked throughout outside, maroon inside, spadix stipitate to 5 mm long; ovate, 11.6--12.5 cm long, broadest below the middle; pistillate portion greenish white, clavate, 2.7 cm long, 1.6 cm diam. at apex, 1.5 cm diam. at middle, 1.1 cm wide at base; staminate portion 10.9 cm long; fertile staminate portion weakly tapered, 1.8 cm diam. at base, 1.6 cm diam. at middle, 1 cm diam. ca. 1 cm from apex, broadest at base, broader than the pistillate portion, narrower than the sterile portion; sterile staminate portion broader than the pistillate portion, 1.8 cm diam.; pistils 4.4 cm long, 1.8 mm diam.; ovary 5-locular, with axile placentation; ovules ca. 14 per locule, 2-seriate, contained within gelatinous matrix (no true envelope), 0.6 mm long, longer than funicle, style 2 mm diam., similar to style type B; style apex rounded; stigma subdiscoid, lobed, 1.5 mm diam., 0.3 mm high, drying lobed, covering center of style apex; the androecium truncate, margins 4--6-sided; thecae oblong, 0.2 mm wide; sterile staminate flowers blunt, 4 mm long, 1.6 mm wide. JUVENILE blades with lower surface dark maroon.