Flora of North America says, "More research is clearly needed on this complex circumpolar entity". It doesn't fit well with other sedges. Whatever section of sedges it's placed with it takes exception. Mostly placed with Paniceae, it's leaf surfaces lack the papillae of other species. Looks like a job for the gene splitters. Sheathed sedge with us occurs in AK, ME, MI, MN, MT, NY, VT, WI, AB, BC, LB, MB, NB, NF, NS, NT, NU, ON, PE, QC, SK, YT, GL, and SPM. Mackinac Co MI, 5/27/17. Sedge family, Cyperaceae.