Stem solitary 4-5 m tall, 7-9 cm diam., smooth surface with overlapping internodes without foliar bases. Leaves 13-18, ca. 2.2 m long; sheath 12- 25 cm long, fibrous; pseudopetiole 80-100 cm long, fibrous, channeled with slightly raised midridge, margins with fibers 6-8 cm long; rachis 1.2-1.4 m long, triangular in cross section at apex; pinnae 98-120 per side, lanceolate, irregularly inserted in groups of 4-10, 4-6 cm apart, open, nearly perpendicular to rachis, plicate at base, green and lustrous adaxially, glabrous with ramenta on central nerve abaxially, in each group the apical pinnae erect to apex; basal pinnae 39-68 X 0.4-0.5 cm; middle pinnae 45-63 X 1-1.2 cm; apical pinnae 4-15 X 0.1-0.2 cm. Inflorescences up to 8 per plant, 40-95 cm long; prophyll 16 cm long, fibrous; peduncular bract 80-92 cm long, apiculate, inflated above, woody, sulcate, brown externally, glabrous and dark brown internally; peduncle 56 cm long, glabrous; rachis 10-13 cm long, glabrous; rachillae 32-46, appressed to rachis, 11-15 bearing 2-4 pistillate flowers, the remaining rachillae with only staminate flowers, basal ca. 8-26 cm long and apical 2.5-10 cm long; sometimes one single rachilla inserted 40 cm from the base of peduncle, with 5-6 pistillate flowers. Staminate flowers sessile, to 6 mm long; sepals and petals apiculate; stamens 6, 2-3 mm long; filaments to 1 mm long; anthers to 2 mm long. Pistillate flowers 9-10 mm; sepals and petals apiculate; ovary glabrous with trifid stigmas; staminodial ring to 2 mm high, undulate. Fruit 3.5- 4 X 2.5-3 cm; epicarp smooth, green with brown scales at apex; mesocarp fibrous; endocarp 5 mm thick covered with persistent coarse fibers, rough surface, beaked at the base and with lightly prominent ridges that stop short of apex; seed 1, endosperm homogenous.