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This keys out to Carex amphibola Steud. or Eastern Narrowleaf Sedge. I originally keyed it out to Carex willdenowii, but Wes Knapp suggested that this could be Carex amphibola instead. It was found in a lot that was disturbed in the past. This species had taken over a large area of the lot. The Flora of Virginia states that species is found in moist old fields among other habitats, and this site fits the bill of a moist old field. The location is Hanover Road and Race Road just inside Howard County, Maryland.