Hemiepiphytic, growing to 15--20 m; stem appressed-climbing (or scandent when preadult), sap reddish, viscous, leaf scars conspicuous, to 4 cm wide; internodes short, 1--2 cm long, (pre-adult length to 15 cm long), (3)6--10 cm diam., glaucous, olive-green to dark green, coarsely white striate near apex, the epidermis with reddish brown patches and reddish brown raised ridges, becoming brown and scurfy, ridged; roots scurfy, short and blunt, dark reddish brown, 5--11 mm diam., feeder root to 3 cm diam., grayish, sparsely and conspicuously warty; cataphylls 30--50 cm long, to 25--30 cm broad at base (when flattened out), more or less D-shaped, unribbed to sharply 2-ribbed (ribs low), greenish white to reddish, thick, juicy, drying reddish brown, persisting semi-intact, eventually as a reticulum of fibers and patches of epidermis; LEAVES: petioles (59)98--137 cm long, (1.5)2--3 cm diam., subterete, medium to dark green, semiglossy, weakly and obtusely flattened adaxially, especially near apex, surface densely and finely short-lineate to faintly striate; blades ovate to narrowly ovate, moderately coriaceous, bicolorous, acuminate at apex (the acumen weakly inrolled), cordate to sagittate at base, (44)81--125 cm long, (30)37--90 cm wide (1.4--1.7 times longer than wide), (0.9--1.2 times longer than petiole), subcoriaceous, margins hyaline, upper surface dark green, velvety, matte, lower surface slightly paler, semiglossy to matte, sometimes tinged pale reddish between veins; anterior lobe 33--102 cm long (3.5--6.1 times longer than posterior lobes); posterior lobes 13--26 cm long, 13--24 cm wide, incurved and overlapping with sinus closed on adult plants, obtuse; midrib flat to weakly convex, silvery-white to yellowish green, paler than surface above, narrowly rounded and slightly paler than surface below; basal veins (3)9--12 per side, first and second free to base, most of remainder coalesced to 4 cm, 2 coalesced to 14 cm; posterior rib naked 1.5--4 cm; primary lateral veins (4)7-10 per side, departing midrib at a 40--60ºangle, arcuate to the margins, narrowly weakly sunken and slightly paler than surface and marginally discolored above, prominently round-raised, paler than surface below; minor veins weakly visible but not distinct below, arising from both the midrib and primary lateral veins. INFLORESCENCES (post-anthesis) to 7 per axil; peduncle 13--16.5 cm long, green, white-striate, especially at apex; prophylls to 22 cm long; spathe 13--16.5 cm long, 5 cm diam., moderately constricted above the tube, weakly glossy; spathe blade 5.8 cm long, white, tinged reddish outside, dark red-violet inside; spathe tube oblong-ellipsoid, 7.5 cm long, purplish violet, short white lineate outside, dark violet-purple, short white lineate inside; spadix sessile; to 12.5 cm long, ca. 1.5 cm diam., constricted above sterile portion; pistillate portion pale green, more or less ovoid, 4.2 cm long in front, 3.4 cm long in back, 2.2 cm diam.; staminate portion 11 cm long; fertile staminate portion to 2.5 cm diam. midway; sterile staminate portion 2.4 cm diam., slightly broader than pistillate portion; pistils 4--6 mm long, 1.4 mm diam.; ovary 4--5-locular, with more or less axile placentation; locules 2.8--5.2 mm long; ovules ca. 20 per locule, 0.1--0.25 mm long, funicle shorter than to equal in length to ovules, style similar to style type B; style crown domed, irregularly lobed; stigma hemispheroid, 1--1.2 mm diam., 0.4--0.7 mm high. INFRUCTESCENCE with berries greenish white; seeds 3--4 per locule, 1.6 mm long.