Black-edge Sedge

Carex nigromarginata, also known as black edge sedge, is a North American sedge which grows on acid soils in dry woodland, thickets, and roadside, and similar ruderal habitats in partial shade or in full sun, often near streams at elevations of 10–800 m (33–2,625 ft). The plants grow in dense clumps, often forming circular patterns on forest floors or roadsides. 2n = 36.