Habit: solitary, erect, to 2 m tall. Stem: 1-1.5 cm diam., ringed, internodes 2-5 cm long. Leaves: 70-90 cm long, spreading, pinnate; sheath 25 cm long, tubular; petiole 6-8 cm long, flattened or broadly grooved above, rounded below; rachis angled above, rounded below; pinnae 10-12 on each side of rachis, middle ones 20 cm long, lanceolate, uppermost shorter and broadly oblong, spreading at nearly right angles from rachis, closely spaced, acuminate, tips recurved, both sides dark green, shining under, midrib prominent and slightly raised on both sides, 8-10 clear inconspicuous primaries per pinna. Inflorescences: Staminate infrafoliar, 50-60 cm long; peduncle to more than 30 cm long; bracts 6, prophyll 2 cm long, 2nd bract 3.5 cm, 3rd 8 cm, 4th 15 cm, 5th 30 cm, 6th 38 cm, tubular, briefly bifid apically; rachillae 20, simple, spreading to drooping. Pistillate not seen. Flowers: Staminate subglobose in bud, aromatic; calyx green, sepals transversely oblong, margins pale; petals ovate-oblong, obtuse, yellow, drying to olive brown or black; stamens shorter than petals, nearly equalling pistillode. Pistillate not seen. Fruits: not seen.