Sandy open ground, bluffs, borders of oak forests, openings among cedars over limestone or other calcareous rock. Very local, flourishing for only a few days in spring or early summer.

This species is sometimes misidentified as Carex pensylvanica, and indeed is somewhat similar in overall appearance to C.pensylvanica (and C. lucorum). It is easily distinguished by the definitely sheathing, purple tinted lower bracts, and the short pedunculate, and more elongate pistillate spikes.

Though a small, unassuming plant, this species is always a pleasure to find, the more so as it typically is an indicator of high quality open habitats on rock or sand, an increasingly rare habitat in modern Michigan.