Leaf blades strongly folded along midribs, curved, 4-10 mm wide. 2n = 20, 30, 40. Flowering Jul-Sep. Pine barrens, wet meadows, margins of ponds, sandy soils; 20-100+ m; Ala., Del., Fla., Ga., La., Md., Miss., N.J., N.Y., N.C., Pa., S.C., Tenn., Tex., Va.