Very large to gigantic root-climber to 60 m. Pre-adult plant forming modest terrestrial colonies. Adult plant with stem 10–35 mm diam., internodes 1.5–20 cm long, separated by prominent leaf scars. Growing stems smooth, glossy dark green, older stems sub-woody to exceptionally corky, mid-brown. Robust foraging stems occasionally occurring. Clasping roots sparse to rather prolific, feeding roots freely produced, often reaching great length, minutely pubescent, later corky, mid- to dark brown, growing tip pale yellow. Cataphylls and prophylls soon drying and falling. Foliage leaves evenly distributed but lower leaves often falling and then leaves tending to become clustered distally. Petiole 33–62.5 cm x 6–20 mm, canaliculate, dark green to slightly glaucous, smooth, air-drying pale brown; apical geniculum 20–25 x 5–12 mm, smooth, basal genuculum 2–4 cm x 7–15 mm, both genicula greater in diameter than petiole, drying shrunken and deeply sulcate, less than petiole diameter and almost black; petiolar sheath extending to half way along the apical geniculum, at first sub-membranaceous, soon drying scarious, later the margin breaking into regular sections which eventually fall to leave a somewhat roughened edges. Lamina 5.5–120 x 8.5–50 cm, entire, oblong-elliptic, slightly falcate, stiffly chartaceous to coriaceous, apex acute to slightly acuminate, base unequal-rounded, one side often produced into a rounded to truncate posterior lobe, glossy bright green, margins hyaline, prominently reddish to yellowish in exposed situations; overall venation densly striate, primary lateral veins simple, 10–15 (-22) per side, 1–1.5 cm distant, diverging from midrib at 70°–75°, often barely or not differentiated from interprimary veins, interprimary veins very numerous, prominent, remaining parallel to primary vein, all higher order venation tesselate; midrib deeply impressed above, very prominently raised beneath, primary venation raised on both surfaces, noticeably so in dried material, higher order venation obscure in fresh and scarcely visible in dried material. Inflorescence solitary, rarely two or more together, first inflorescence subtended by a fully to partially developed foliage leaf with a well developed petiolar sheath. Peduncle 5–8 cm x 4–10 mm, stout, terete, bright green. Spathe canoe-shaped, shortly but stoutly tapering, stiffly coriaceous, gaping at anthesis, 16–33.5 x 5.5–16 cm when pressed flat, exterior green, interior waxy-glaucous to deep yellow at anthesis, air-drying mid-brown. Spadix 15.5–28.5 x 1.5–4.5 cm, sessile, cylindrical, bluntly tapering towards the apex, orange at anthesis, air-drying mid-brown. Flowers 2.5–4 mm diam. Stamens 4; filaments 1 x 0.5 mm; anthers narrowly ellipsoid 2 x 0.75–1 mm; ovary 3–10 x 2.5–4 mm, ellipsoid, basal part strongly compressed; ovules 2; stylar region 4–10 x 1.5–4 mm, trapezoid, robust, apex flattened, margins reflexed in dry material; stigma linear, 0.8–3 x 0.1–0.5 mm, longitudinal. Fruit light-green, reipening to dull orange, stylar region greatly enlarged. Seeds slightly curved, c. 5 x 2 mm, glossy pale brown.