Hydriastele costata F.M.Bailey

Palm to 35 m tall; trunk to 40 cm diam. Leaves 10–15, to 4 m long, straight, but lower ones tending to droop; leaf sheath to 150 cm long, light green suffused with lilac, with dense grey tomentum. Pinnae 80–120 each side of rachis, regularly arranged, to 127 cm long, acuminate, laxly pendulous, green on both surfaces. Inflorescence to 125 cm long, branched to 2 orders; rachillae to 62 cm long, flexuose, at first erect but pendulous in fruit. Flowers white, opposite, protogynous. Staminate flower to 10 mm long; pistillode lacking. Pistillate flower globose, to 3 mm high. Fruit ovoid, to 10 mm long, to 5 mm diam., deep maroon with few blue grey longitudinal stripes; epicarp smooth; mesocarp thin, fleshy; fibres dense and thick; endocarp crustose. Seed globose to ovoid, to 4 mm diam.

An emergent or canopy palm found in primary or secondary lowland rainforest often on swampy ground, or more infrequently lower montane forest on less waterlogged ridges and slopes; at elevations up to 700 metres.

Can be grown by seedlings.