Moist openings, stream borders, and roadsides in swampy (chiefly coniferous) forests; moist shores and thickets.

Usually in more sterile, acid sandy or gravelly soils than Carex crinita; the two only occasionally co-occurring. While looking quite similar, a check of the green portion of the leaf sheaths (the "back") will disclose the minute scabrousness of C. gynandra.