A genus of about 75 species, herbs, cosmopolitan. The separation of Nasturtium from Rorippa is warranted (Al-Shehbaz & Price 1998); Franzke et al. (1998) provide corroboration based on molecular analysis. The species treated here as R. aquatica has been placed in several genera in recent years.
Ref: Al-Shehbaz (1988a); Al-Shehbaz (1988a); Al-Shehbaz (2010a) In Flora of North America Editorial Committee (2010); Al-Shehbaz & Bates (1987); Al-Shehbaz & Price (1998); Franzke et al. (1998); Les, Anderson, & Cleland (1995); Rollins (1993); Stuckey (1972). Show full citations.