Stem climbing, 20–25 ft. long. Leaves about 5 ft. long, ovate, patent; sheath cylindrical, tight, unarmed below, with transverse rows of recurved subulate-conical spines above, oblique and furnished with very acute spines at the mouth; petiole semiterete, 3 in. long, 6 lin. thick, slightly channelled above, margins and back with a few erect subulate spines 9–12 lin. long; leaflets linear-lanceolate, much contracted at the base, acuminate, about 35 on each side, alternate, equidistant, 7-nerved, with black bristles on the margins and under (rarely upper) side of the nerves, and minute light brown scales on the undersurface; central leaflets 14–15 in. long, 12–14 lin. wide, 1–1 1/4 in. apart; terminal leaflets 6 in. long. Spadix elongate, slender, decurved, main axis prolonged into a very long terete naked appendage, primary branches twice or thrice simply branched; peduncle connate at the base with the sheath of the uppermost leaf; spathes long, cylindrical, obliquely split at the apex, the lowest about 1 ft. long, ancipitous and distantly spinulose on the margins, the upper unilateral and sparingly spiny; bracts cup-shaped, obliquely acuminate, bracteoles dense, smaller than the bracts and less acuminate; flower-bearing branches 2 in. long. Male flowers 3 lin. long, solitary, yellow. Calyx cup-shaped, trifid; lobes broadly-ovate. Corolla twice as long as the calyx, tripartite; lobes oblong-ovate. Stamens 6; filaments subulate, united at the base; anthers linear-oblong, sagittate at the base. Rudiment of ovary glo-bose; stigmas 3, long. Female flower enclosed in a bracteole together with a male or neuter flower, yellow. Calyx and corolla as in the male. Staminodes 6. Ovary oblong; stigmas 3, shortly recurved, triangular. Fruit ovoid, attenuate at the apex, 7–8 lin. long, 4 lin. diam.; scales in 19–21 rows, rather convex, marked with a shallow median furrow, shining, margin membranous, erose, brown. Seed 4–5 lin. long, oblong-ellipsoid, slightly compressed, rugulose; chalaza dorsal, incrassate; albumen horny; embryo basal, erect, close to the hilum.
