Rare in Michigan, in swamps (e.g., dense maple-ash floodplain forests), especially fond of margins and bottoms of vernal pools and often associated with major river systems; in Michigan primarily the Grand River system, but also known from the Huron and Rouge River drainages. 

Perhaps somewhat overlooked since it fruits later than many Carex, maturing fruits even into early September. See the notes under the much more frequent Carex squarrosa.