Appressed-climbing hemiepiphyte, sometimes on rocks; stems about 1 m long, sometimes longer; internodes shorter than broad, 2.5-5 cm diam., light brown with irregular, weak, reticulate to mostly transverse fissures, turning yellow-brown; petiole scars to 4.5 cm diam.; cataphylls sharply D-shaped near apex, otherwise terete and unribbed or sometimes bluntly 2-rlbbed, green to pale orange (sometimes brown, orange at base) or reddish, promptly caducous; roots moderately few, stout, ca. 5 mm diam., purplish brown, drying smooth, semiglossy, the epidermis often fissured. LEAVES usually clustered near the end of the stem, with erect spreading petioles and pendent blades; petioles broadly spreading, 25-57 cm long, averaging 40 cm long, broadly sulcate at base, obtusely flattened toward the apex, weakly angular near the apex, sheathed 4-8 cm at the base, firm, olive green to golden-yellow, pale yellow-orange or greenish yellow, when fresh, somewhat asperous and rather densely purplish-lineate, drying light yellow-brown to dark brown, typically closely fissured; blades pendent, narrowly triangular to narrowly ovate-triangular to oblong-triangular, 30-85 cm long, 8.1-21 crn wide (averaging 52 x 15 cm), 2.7-4 times longer than wide, averaging 3.4 times longer than wide, broadest at the base or near the petiole attachment, sometimes weakly constricted above the petiole attachment, 0.85-1.4 times as long as the petioles (averaging 1.07 times longer than petioles), moderately coriaceous, dark green and semiglossy above, much paler and matte to weakly glossy below; the margins often weakly undulate, hyaline or reddish; posterior lobes directed at about 170º from the midrib (the two lobes separated by an angle of 35-40º), sometimes directed up slightly at an angle to the midrib, 8-22 cm long, 3-10 cm wide, about twice as long as wide; sinus much longer than wide, acute at apex, usually barely naked along the margin, but sometimes weakly naked up to 2.5 cm (the leaf tissue merging almost imperceptibly with the posterior rib); midrib flat to very broadly raised and paler (sometimes orangeyellow) with purplish dots above, narrowly raised and convex, yellow-brown to yellow-red or yellowgreen below; primary lateral veins 3-5, widely spaced and usually not prominent, weakly sunken to flat and yellow-green above, convex to weakly raised and sometimes reddish to purplish below, arising at 70-105º angle, mostly at nearly 90' angle, sometimes prominently down-turned at the midrib, sometimes splayed out at the midrib; minor veins numerous, moderately distinct when fresh, weakly raised above, flat and distinctly visible below, drying prominulous on both surfaces, with alternate veins frequently turned to join another minor vein just before the margin; cross veins inconspicuous; young leaves reddish. INFLORESCENCES 1-3 per axil, erect; peduncle 9.4-27 cm long, ca. 1 cm diam., somewhat flattened, ribbed on one side, medium yellow-green, green-lineate to purplish-lineate; spathe 17.5-18.5 cm long, yellow-green to dark green outside, slightly paler toward apex, densely pale purplish-lineate on tube, dark purplish-lineate on blade, the outer margin of the tube slightly paler, the blade white to greenish white within, the margins weakly turned back at anthesis; tube sometimes reddish-spotted outside, mauve to maroon within, becoming dark maroon-purple within after anthesis with conspicuous, closely spaced resin canals restricted to the area of the constriction, blending in with the red of the tube and the white of the blade; spadix 16.5- 18 cm long; staminate portion white, to 9 cm long, to 11 mm diam. at base, weakly constricted to ca. 9 mm somewhat above the sterile portion, tapered to the narrowly rounded apex; pistillate portion pale green, to 7.2 cm long on front side, 5.3 cm long on back side; pistils ca. 3 mm long, pale yellowgreen, turning pale yellow post-anthesis; ovaries 6- 1 l-locular; ovules more than 10 per locule; sterile male flowers broader than the pistillate portion, scalloped and undercut at base, 2.2 cm diam., 10-11 mm long; fertile portion constricted 8.5 cm above base, creamy white, bluntly pointed at apex.