Syst. Veg. 3: 828. 1826
Phenology: Fruiting Jun–Aug.
Habitat: Marshes, wet prairies and meadows, open swamps, wet, open thickets, open stream, pond, and lakeshores, ditches, often in water (to 60–80 cm deep)
Elevation: 50–2800 m
Alta., B.C., Man., N.W.T., Ont., Que., Sask., Yukon, Alaska, Ariz., Calif., Colo., Idaho, Ill., Ind., Iowa, Maine, Mich., Minn., Mo., Mont., Nebr., Nev., N.Mex., N.Y., N.Dak., Ohio, Oreg., Pa., S.Dak., Utah, Vt., Va., Wash., W.Va., Wis., Wyo., Eurasia.
Carex atherodes is a major wetland species in portions of the Midwest and West and becomes increasingly uncommon and local in the eastern portions of its range. It forms large clones and can tolerate deeper water than most Carex. Glabrous forms occur and seem to be more common in the western portion of the range.
Carex atherodes rarely hybridizes with C. trichocarpa.