Rorippa islandica var. occidentalis (S. Watson) Butters & Abbe
Rorippa islandica var. occidentalis (S. Watson) Butters & Abbe is a synonym sensu FNA Ed. Comm., 2010 of:
Rorippa palustris (Linnaeus) Besser subsp. palustris, an accepted subspecies name sensu FNA Ed. Comm., 2010.