Distribution: Occurring west of the Cascades crest in counties along the Puget Sound and outer coast; British Columbia south to Oregon, east sporadically across the U.S. to the northern Atlantic coast of the U.S. and Canada; circumboreal.
Habitat: Coastal salt marshes.
Origin: Both native and introduced - occurring in eastern North America, Eurasia.
Conservation Status: Not of concern
Rhizomatous perennial 3-7 dm. tall.
Leaves alternate, the blades flat, 1.5-3 mm. broad; leaf bases sheathing, the sheaths several, the uppermost extending to above midlength of the flowering stem.
Inflorescence many-flowered, loosely cymose, 3-10 cm. long; perianth 3-4 mm. long, the 6 segments dark brown with a greenish mid-stripe, blunt, and hooded at the tip; stamens 6, the anthers much longer than the filaments.
Capsule ovoid to obovoid, rounded, about equal to the perianth.