Carex vulpinoidea #1 (Fox Sedge)

Fox Sedge is a robust, bright green,  clumping wetland sedge, growing to nearly 4′ tall and as wide. It thrives in disturbed, low-quality wetlands and spreads aggressively in areas with diminished competition, leading to large colonies. The flowers mature into bristly, brown seed clusters that resemble fox tails. The seeds are eaten by many bird species and the plant is host to several species of skippers and Lepidoptera. When extensive colonies do form, they provide excellent cover for wildlife.

Sources:
Missouri Botanical Garden
Lady Bird Johnson Wildflower Center
Illinois Wildflowers
Grow Native! Salt-Tolerant Native Plants