Long trailer and climber; trunks 1-2.5 cm. thick, glabrous and nude: leaves 2 m. long, with many large-alternate pinnae becoming opposite on the upper part where they pass into 3 or 4 pairs of retrorse glabrous strong heavily based spines 3-.5-4.5 cm. long; petiole and rachis sharply angled, glabrous or at places slightly furfuraceous, bearing a few straight spines 1-2 cm. long with now and then a stout broad-based sharp curved hook 3 mm. long; leaf-sheath many-striate and bearing many dark brown flat spines 5 mm.-2.5 cm. in length; pinnae long-lanceolate- acuminate, 15-24 cm. long, 2.5-4 cm. broad at middle, glabrous on both surfaces or with a trace of puberulence underneath, margins unarmed, midrib pronounced but the several side-veins indistinct, upper surface sometimes marked by elevated cross-lines, usually a spine 1.5-2 cm. long borne on midrib underneath at about the middle or toward the base: main or inner cymba 24 cm. long, 5-6 cm. broad, densely covered with blackish white-bottomed spine-like setae 1 cm. more or less long; primary spathe short and narrow; sheath of openly woven fibers and many blackish spines; spadix at anthesis 12-15 cm. long and 10 cm. broad, the glabrous rachillae later extending and likely to be fertile to the ends: fruit ellipsoid, nearly or quite 2 cm. long when dry and 8 or more mm. broad, abruptly pointed, glabrous; cupule not very prominent, inner series undulate or lightly indented and much more extended than the small ring-like calyx; seed 13-14 mm. long, 6 mm. thick, narrowly oblong, closely reticulated with light-colored rapheal lines issuing from the central micropyle that attaches to the outer shell of the fruit, and 2 pores prominent on the back.