Moist, usually sandy meadows and prairie remnants.

An occasional, especially immature, specimen of C. tetanica might be keyed here, if the perigynia are not clearly tapered at the base and thought to be impressed-nerved; C. conoidea has strongly rough-awned pistillate scales, a very scabrous inflorescence axis, and is cespitose. The two can co-occur.

The Farwell collection from Cedar Creek, Keweenaw County seems out of range, but it was collected late in his life (No. 12407, collected July 3, 1940), and seems not to be problematic. Carex conoidea often occurs sparsely within its habitat and is easy to overlook.