Typical pallida occurs mostly in marshy habitats of northeastern states and adjacent Canada. Closely related plants (varieties or subspecies) occur in western North America and East Asia (FNA 24, Kowano & Koyama 1964). The only Ky. records are from two swamps in western regions during the 1970s, plus a coll. of H. Griswold via C.W. Short from JEFF (PH) in the 1830s.