One of our commonest species, in wet ground everywhere (except sphagnum bogs, as it prefers calcareous sites), especially on shores, along ditches and edges of streams and lakes, and sedge meadows and edges of marshes.

The terminal spike frequently has some perigynia at the base or apex. Occasional sterile plants intermediate with C. pseudocyperus or, less commonly, C. comosa occur and are presumably hybrids.

Resembling the more local and southern Carex lurida (which, however, prefers acidic soils), in the field the spikes are distinctly yellowish, and the lowest typically is conspicuusly pedunculate. In C. lurida, the spikes are darker, even olive-green at maturity, and even the lowest spike is typically only short-peduncled or essentially sessile.

The much less common Carex schweinitzii is also the same yellowish tone and also occurs in calcareous settings, but is colonial from long-creeping rhizomes, not clumping, and forms clonal patches in springly ground, especially along streams.