Hemiepiphyte to 1.5 m tall; internodes 1.2-15 cm long, 1.2-2.5 cm in diam., dark green, coarsely short-lineate on lower edge of nodes, with transverse fissures, epidermis turning brown and semiglossy; roots dark brown, 3-5 mm in diam. Cataphylls to 38 cm long, 3 cm in diam. at the base, mostly unribbed but weakly 1-ribbed near the apex, green with reddish base and shortly palelineate, turning light yellow-brown, then dark brown, rigid and glossy, persisting ± intact at upper nodes, eventually breaking off except for the persistent base. Petioles (14-)30-40 cm long, 3-7 mm in diam. at the middle, terete, dark green, semiglossy, weakly short-lineate to striate toward the apex, sheathed to 9 cm long; geniculum to 4 cm long, 9 mm in diam., paler on abaxial side, sometimes pale pink at point of insertion with the blade. Leaves pendant, then spreading-pendant from erect-spreading petioles; blades narrowly ovate-elliptic, (27-)45-60 × (9-)16.5-27 cm, 2.4-3.2 times longer than wide, dark green, pinkish to reddish when young, semiglossy above, moderately paler and slightly glossier below, drying grey-green to brownish, with weakly visible resin canals on upper surface, yellowish grey-green to brownish with the cross-veins moderately visible on lower surface; gradually long-acuminate at apex, subcordate at base, the lobes sometimes unequal; sinus 2-2.5 cm deep, narrow; midrib prominent, rounded and moderately paler, yellow-green above, narrower and bluntly acute, almost concolourous below; basal veins in 2-3 pairs, all free to base; primary lateral veins (11-)17-21 per side, moderately sunken, sometimes weakly quilted and concolourous above, narrowly raised and concolourous below, arising at 65-75° angle, broadly arching to the margins; interprimary veins usually present; minor veins moderately obscure. Inflorescence solitary; peduncle 3-3.5 cm long, 8-12 mm in diam., pale green, semiglossy, faintly striate, especially toward apex; spathe 15.5-19.5 × 6 cm at anthesis (flattening to 8.5 cm wide), clearly demarcated from the peduncle, reddish violet (B & K red purple 3/5; Berlin & Kay 1969) on tube outside, paler and reddish violet (B & K red purple 3/5) tinged toward apex, eventually whitish toward apex outside, dark maroon inside, only slightly paler toward apex, except whitish along the margin inside, lacking a constriction and opening nearly to the base at anthesis with most of the spadix fully exposed; spadix protruding forward at anthesis, to 17.7 cm long; the pistillate portion 5.8-6.3 cm long in front, 3.7-4.2 cm long in back, 1.2-1.4 cm in diam., pale yellow-green; staminate portion 8.5-11.5 cm long, 1-1.4 cm in diam. at base, 1.3-1.4 cm in upper 2/3 and 1 cm in diam. at 1 cm from the apex, lacking any obvious constriction above the sterile portion; sterile staminate portion scarcely distinguishable from fertile portion and with the flowers loosely grading into the pistillate portion with a few isolated sterile flowers mixed among the pistillate flowers; pistils 2 mm long, the stigma depressed-globose, 1 mm in diam., locules 4-6; ovules 3-5 per locule, along with the funicle 0.2-0.3 mm long, borne within a translucent envelope c. 0.6 mm long, the funicles about as long as the ovules, ovules well spaced along one margin of the envelope.
Planta hemiepiphytica, ad 1.5 m; internodia 1.2-15 cm longa, 1.2-2.5 cm diam.; cataphylla ad 38 cm longa, debiliter 1-costata ad apex; petiolus (14-)30-40 cm longus, 3-7 mm diam., teres; geniculum ad 4 cm longum, 9 mm diam.; lamina anguste ovata-elliptica, (27-)45-60 cm longa, (9-)16.5-27 cm lata; nervis lateralibus (11-)17-21 utroque; inflorescentia solitaria pedunculo 3-3.5 cm longo; spatha 15.5-19.5 cm longa, 6 cm lata per anthesis, rubroviolacea vel marronina, sine constrictio; spadix protrudens, ad 17.7 cm longus, parte pistillata 5.8-6.3 cm longa, parte staminata 8.5-11.5 cm longa, pistillis 4-6-locularibus ovulis 3-5 per loculum.