Porteresia coarctata (Roxb) Tateoka  Perennial grass, 1-2 m tall  Rhizome thic, creeping  Leaves linear, coriaceous with spinulose margins.  Panicles spiciform, branched, each with a few flowers  Glume 1 and 2 setaceous, glime 3 smooth, dorsally winged into an awn  Lodicules subquadrate, membranous