Carex nigromarginata

Carex nigromarginata 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. The plants grow in dense clumps, often forming circular patterns on forest floors or roadsides. 2n = 36.

Range
Ontario, west to Illinois, Missouri, and Arkansas, south from Mississippi to South Carolina and northeast to Rhode Island, Connecticut and Massachusetts.