This is a species of acid, sandy soils of wet meadows and openings in forests. The only Michigan collection with habitat data is from Midland Co.: “woods along Salt River” (R. R. Dreisbach 8056 in 1934, MICH). A collection from the herbarium of William Boott (MSC) from “Grass Lake” in 1858 is presumably from Jackson Co.

This is quite similar to Carex stricta, but the rhizomes are short-creeping only, not elongate, so this does not so regularly form large colonies. Also the culms typically exceed the leaves and are topped with short inflorescences with short brownish spikes, often diverging from the inflorescence axis at a significant angle, allowing one to make an educated guess as to its presence from a modest distance. 

The range of Carex haydenii is divided peculiarly into two parts. It is moderately frequent from New York through New England and adjacent Canada, south sparingly in the Appalachians to Maryland and West Virginia. Then it also occurs more or less frequently from Minnesota and adjacent Canada south through western Indiana, Illinois, and Missouri, and irregularly west to the Black Hills. Michigan, Ohio, eastern Indiana, and parts of Ontario directly north form a gap where the plant is absent or very rare.