Cool-season, vigorously rhizomatous, loosely tufted, perennial grasslike. Occurring along tidelines, estuary meadows and salt marshes in coastal areas; also found inland up into montane streamsides, pond edges and wetlands. Tolerant of saline soils and salt spray. Can form extensive pure stands, especially on disturbed ground. Palatable to cattle. Provides food for waterfowl and upland birds; roots eaten by muskrats.