Appressed-climbing hemiepiphyte to 1.5 m, epiphytic or occasionally on ground or rocks; stems apparently scandent. Internodes dark green to grey-green, (1-)2-3 cm long, (1.2-)1.7-2 cm in diam., becoming yellow-brown and semi-glossy, sharply flattened on one side, occasionally with acute marginal ribs. Cataphylls green, soft, deciduous, sharply 2-ribbed, 16 cm long, pale green, the ribs to 3-4 mm high, flaring, sometimes with spreading wings. Leaves with petioles spongy, subterete, dark green and semi-glossy, sometimes striate or densely short-lineate, conspicuously constricted and darker at apex where it meets the midrib, obtusely flattened adaxially; blades subcoriaceous, moderately bicolourous, semi-glossy, narrowly triangular-ovate, (25-)32-37 × (9-)11.5-18 cm, acuminate to cuspidate at apex, narrowly cordulate at base, posterior lobes (3-)4.3-4.5 × 2-4.5 cm midway, sinus v-shaped, 3-4 cm deep and 6-7.5 cm wide, narrowly rounded at apex; midrib convex and slightly paler above, narrowly rounded and paler tomuch paler below; primary lateral veins 4 to 5 per side, departing at 85° angle, then spreading at 60° angle near the margin, obtusely sunken to weakly quilted and concolourous above, convex and paler below; minor veins sparse, weakly visible below. Inflorescences 2 or 3(-5) per axil; peduncle 11.5-12 cm long, (3.5-)6-8 mm in diam., medium green, semi-glossy; spathe 5-13 cm long, semi-glossy, sometimes glossy, medium to dark green, paler green on blade outside, purple-tinged on open edge outside, pale green to whitish inside; spathe tube (0.8-)1.7-2.2 × 2.4-2.6 cm, dark purple-violet to dark maroon in lower 1/2 to 2/3 inside; spadix ivory throughout, 4.5-7.5 cm long; staminate portion 3.3-5.9 cm long, sometimes weakly protruding after anthesis, sterile staminate portion 8-9 mm in diam., middle of fertile staminate portion 9mmin diam., at 1 cm from tip, 5mmin diam.; pistillate portion 3.5-4 cm long in front, 3-3.5 cm long in rear, 0.8-0.9 cm in diam. at base, 1.2-1.4 cm in diam. midway, 1-1.2 cm in diam. at apex; pistillate flowers pale to medium green before anthesis, creamy white after anthesis; pistils medium green in early fruit; immature fruits pale green.