Calamus siphonospathus var. siphonospathus

Stems solitary, to 30 m long and 5 cm diameter (with leaf sheaths); leaf sheaths yellowish-brown, sparsely covered with needle-like, yellowish spines to 1 cm long; knee obscure; ocreas present, membranous; flagella absent; petioles to 20 cm long; pinnae to 50 per side of rachis, linear, regularly arranged, closely spaced to 2 cm apart; cirri present, to 1 m long. Inflorescence bracts open and diameter, yellowish-brown.

This species is known only from the Philippines, and just reaches Taiwan on Lanyu Island. It is very variable morphologically, and six varieties are recognized (Lapis, 1987). The Taiwan plants were placed, without discussion, in var. sublevis Becc. by Chang (1988).