Hydriastele costata F.M.Bailey
Bailey, F.M. (1898) Queensland Agricultural Journal 2(2): 129. Type: Somerset, Cape York Peninsula, Nov. 1897, Frank L. Jardine.
Solitary palm to 35 m tall, to 40 cm dbh, expanded at base; leaf scars to 35 mm wide; internodes to 25 cm long, smooth, grey.
Usually 10-15 leaves, each to 4 m long, held out straight but lower ones tend to hang below horizontal; with 80-120 pinnae each side of rachis. Crownshaft to 150 cm long, light green suffused with lilac, with dense gray tomentum. Petiole 15-40 cm long; rachis to 350 cm long. Pinnae regularly arranged, to 127 cm long, acuminate, pendulous.
Inflorescence to 125 cm long, 40 cm wide. Flowers in threes, 1-2 male. Male flowers 10 mm in bud, not opening widely; sepals 1-1.5 mm x 1-1.5 mm, green; petals 9-10 mm x 3-5 mm, cream; stamens 6-24, 5-7 mm long; filaments 0.5 mm long; anthers 2-3 mm, bright yellow. Female flowers 1.5-3 x 2-3 mm in bud; sepals 0.2-0.5 x 0.5 mm, light green; petals 2-2.5 x 2-2.5 mm, cream-green; stigmas 0.2 mm long.
Features not available.
Distinguished from other species of Hydriastele by the solitary habit, regularly arranged, pendulous pinnae, the straight leaves and fruit to 10 mm long.