This circumboreal species of northeastern salt marshes has spread inland to disturbed areas at scattered sites, usually along railroads and major highways (FNA 22, Y). The only Ky. record is a 1978 coll. by P.C. Applegarth from an area treated for oil spill along a railroad in KENT (KNK). It has more distinctly elongated rhizomes than any other Juncus in Ky.