Caulis angularis. Folia coriacea, sessilia vel subpetiolata; lamina anguste elliptica vel oblanceolata, apex acutus vel obtusus subpeltatus, basis attenuata, semi-amplexicaulis, non decurrens; nervi longitudinales paralleli 8-10. Ascidia ellipsoidea, cum alis duabus prominentibus; os obliquum. Peristomium applanatum expansum, margo exterior distincte sinuatus, costae distinctae. Inflorescentia mascula racemosa; pedicelli uniflori. — Holotypus: Kostermans 14017 (L – HLB 960.112- 783 & 784), East Borneo, Bcrouw, top of Mt Has Mapulu, alt. 800 m, 23-9-1957. Stems angular, 5-6 mm thick, internodes 2-4 cm long. Leaves coriaceous, sessile or shortly petiolate; lamina narrowly elliptic or oblanceolate, 13-26 x 2.2-5 cm, apex acute, subpeltate; base attenuate, semi-amplexicaul; longitudinal nerves originating from lower 1/4 of the midrib, running 4-5 on each side; pinnate nerves distinct; tendrils of pitchers flattened, grooved, not curled, wider towards the pitcher, 3-4 mm thick near the pitcher, 1-2 mm thick near the leaf tip, 45-50 cm long, 1 to 2 times longer than lamina length; tendrils without pitchers slender, usually shorter than lamina length, 4-25 cm long. – Pitchers ellipsoidal, 11-21 cm high, 7-8.5 cm wide immediately below peristome, with 2 prominent fringed wings running over the entire length, wings 2-10 mm wide; mouth oblique; peristome flattened, expanded, 2-20 mm wide, broader in the middle, outer peristome margin distincdy wavy, peristome ribs 0.5 mm apart, inner peristome teeth distinct; inside surface of the pitcher glandless in the upper half, glandular with numerous minute glands in the lower half; lids 4.5-8 x 3-4 cm, the lower surface with a central glandular ridge and numerous glands concentrated around the ridge and towards the base, glands on the ridge large and distinct. – Male inflorescence racemose; peduncle 7 cm long; pedicels 4-8 mm long, 1-flowered, bractless; sepals 4, lanceolate, 2.5-3 x 1.5-2 mm; staminal column 2.5-3 mm long; anthers uniseriate. Female inflorescence unknown. Fruits unknown. – Indumentum of very short branched hairs on midribs, tendrils, pitchers, and inflorescences. Leaves glabrous above and below, the lower surface with dark brown spots. Margin of leaves sometimes ciliate.