Sp. Pl. 1: 338. 1753 (as palustre).
Plants with fibrous strands of leaves at base, 9–42.5 cm. Leaves erect from sheath, shorter than scapes, 6–24.5 cm; sheath 3.5–5 cm × 1.5–5 mm, ligule not hoodlike, unlobed; blade 0.8–2.9 mm wide, apex acute. Inflorescences: scape often purple near base, mostly exceeding leaves, 5.5–27.2 cm × 1–2.1 mm; racemes 5.1–21.4 cm × 2–5 mm; pedicel 0.4–4.5 × 0.1–0.5 mm. Flowers: tepals elliptic, 1.1–1.6 × 0.7–0.9 mm, apex round; pistils 6, 3 fertile, 3 sterile. Fruits: fruiting receptacles with wings; schizocarps linear, 7–8.3 × 0.8–1.2 mm; mericarps linear, weakly ridged abaxially, 6.5–8.5 × 0.5–1.5 mm, beak erect, 0.3 mm. 2n = 24.
Phenology: Flowering summer and early fall.
Habitat: Coastal and mountain marsh areas and moist alkaline meadows
Elevation: 0–3700 m
Greenland, St. Pierre and Miquelon, Alta., B.C., Man., N.B., Nfld. and Labr., N.W.T., N.S., Nunavut, Ont., P.E.I., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Ill., Ind., Iowa, Maine, Mich., Minn., Mont., Nebr., Nev., N.H., N.Mex., N.Y., N.Dak., Ohio, Oreg., Pa., R.I., S.Dak., Utah, Wash., Wis., Wyo., Mexico, South America, Eurasia.