Swamp loosestrife
- kingdom: Plantae
- phylum: Tracheophyta
- class: Magnoliopsida
- order: Myrtales
- family: Lythraceae
- genus: Decodon
- species: Decodon verticillatus
- Canada
Ludlow
MassachusettsEast Grand Rapids
Greenville
Haslett
Williamston
MichiganCarlstadt
East Rutherford
Hasbrouck Heights
Wood-Ridge
New JerseyBorough of Bronx
New YorkKingston
Rhode IslandWashington, D. C.
Washington, D.C.Elkhorn
Wisconsin
United States