Hemiepiphytic to epiphytic; appressed-climbing, leaf scars inconspicuous, 2 cm long, 2--2.5 cm wide; internodes moderately smooth and glossy, loosely and irregularly ribbed and grooved, 2.5--7.5 cm long, 2--5 cm diam., green to gray, soon brownish and more or less densely transversed-fissured to scurfy and glossy to semiglossy, drying pale yellowish brown; epidermis flaking; roots 1-few per node, reddish brown; cataphylls 20--31 cm long, D-shaped to sharply 2-ribbed, green, spotted with purple, persisting intact at upper nodes, eventually deciduous; LEAVES: petioles 34--41 cm long, 1--1.5 cm diam., subterete to obtusely flattened or obtusely D-shaped adaxially, especially toward toward apex, medium to dark green, surface densely pale lineate, purple spotted; sheathing up to 3/4 its length; blades ovate to narrowly ovate, subcoriaceous, semiglossy, moderately bicolorous, abruptly acuminate at apex, cordate to subcordate at base, 34--63 cm long, 17--33 cm wide (1.8--2.2 times longer than wide), longer than petiole, upper surface drying gray to gray-brown, lower surface drying yellow-brown; anterior lobe 29--51 cm long, margins convex; posterior lobes 6--17 cm long, 6--13 cm wide, directed downward; sinus arcuate to V-shaped or rarely parabolic, (4)6--12 cm deep; midrib flat to concave, paler than surface above, convex to narrowly rounded, maroon-spotted and darker than surface, drying paler than surface below; basal veins 3--4 per side, second and higher (or sometimes only third and fourth) coalesced 0.5--4.5 cm; posterior rib not at all naked; primary lateral veins 5--6 per side, departing midrib at a 60--75º angle, weakly curved to the gradually curved downward just before reaching the midrib, weakly sunken and paler above, convex and darker below; minor veins moderately distinct to more or less obscure, arising from both the midrib and primary lateral veins, drying minutely undulate. INFLORESCENCES 1 per axil; peduncle 7--9 mm long, 9--12 mm diam., more or less terete, light green, sometimes faintly tinged reddish medially on one side, clearly demarcated from spathe; spathe semiglossy, 10--13.5 cm long, 2--2.5 cm diam. midway, weakly constricted above the tube, oblong-ellipsoid, abruptly acuminate at apex (the acumen ca. 8 mm long); spathe blade greenish yellow outside, pale green, faintly striate inside, resin droplets forming on blade surface within; spathe tube 5 cm long, dark violet-purple with thin greenish margin (ca. 5 mm wide) and along a narrow band adaxially, faintly pale striate-speckled to faintly pale lineate outside, dark maroon inside; spadix sessile; gradually tapered to a blunt apex, 7.3--11.5 cm long; pistillate portion greenish, 4 cm long in front, 3.2 cm long in back, 1.2 cm diam.; staminate portion 7.3 cm long; fertile staminate portion 1.4 cm diam. at base, 1.1 cm diam. at middle, 8 mm diam. ca. 1 cm from apex, broadest at the base; sterile staminate portion 1.4 cm diam.; pistils 2.3 mm long; ovary 7-locular, 1.7 mm diam., with sub-basal placentation; ovules 3(4) per locule, contained within gelatinous matrix (no true envelope), 0.5 mm long; funicle 0.3 mm long (can be pulled free to base), style 1 mm diam., similar to style type B; style apex flat; stigma lobed, 1 mm diam., 0.2 mm high, covering apical depressions (forming a ring without papillae in the center of the apex), depressed medially; the androecium truncate, prismatic, irregularly 4--6-sided, mostly 4--5-sided, 0.9--1.2 mm long; sterile staminate flowers irregularly 4--5-sided, prismatic, 1.3--1.8 mm long.