Cool season, rhizomatous, native perennial grasslike common in many western states. Occurs in saturated soils of wet meadows and springs, from foothills to moderate elevations up to 9,000 ft. Often found on gentle slopes below seeps and on flat areas next to streams, sometimes in dense stands. Tolerates partial shade. Well-adapted to soils rich in organic matter but also to fine-textured saturated mineral soils. Useful for wetland and riparian restoration.