Pers., Synops. Pl. 2:532.1807
Large, monoecious, semiaquatic herb 1-3 m tall; rhizomes long, fleshy. Leaves equitant; blades sword-shaped, acute at apex, ensheathing stem at base, more than 1 m long, 3-10 mm wide. Inflorescences cylindrical, elongate, 1-2.5 cm diam, 50-120 cm long; flowers in dense spikes, the staminate flowers above the pistillate, separated by 3-10 cm of naked peduncle; perianth reduced to bristles; pistillate flowers usually having filiform bractlets with dilated tips; ovary stipitate, l- or 2-celled. Mature inflorescences becoming fluffy with loosening comose nutlets; mature nutlets ca 1 mm long, attached to a slender stipe ca 5 mm long. Croat 4671.
Rare, along the shore. Fertile in the dry season. This linear-leaved aquatic is confused with no other plant.
The persistent perianth bristles assure wide dispersal in the wind.
Widely distributed in tropics and subtropics throughout the world. In Panama, in marshy areas; known from tropical moist forest in the Canal Zone and Bocas del Toro and from premontane dry forest in Los Santos.