Scientific name

Rorippa Scop. (including Nasturtium R. Br.)

Common names

yellow cress, water cress



Could be confused with

Cardamine, Oenanthe

Native distribution

cosmopolitan, mostly through introductions

Species commonly cultivated

Rorippa nasturtium-aquaticum (L.) Hayek (Nasturtium officinale R. Br.) (Europe and northern Asia)

Rorippa aquatica (Eaton) E.J. Palmer & Steyerm. (Neobeckia aquatica (Eaton) Greene) (North America)

Adventive distribution

Numerous Rorippa species have been introduced on most continents, particularly in temperate regions; Rorippa nasturtium-aquaticum is widely distributed and has become almost cosmopolitan.

Weed status

Rorippa are noxious weeds around the world and in some states in the United States. Most of these are not exclusively aquatic, but tolerate periodic inundation. Rorippa nasturtium-aquaticum is a common weed of irrigation canals and natural waterways but is rarely problematic.


emergent herb with large, erect inflorescence

Brief description

Annual or perennial. Stems compact to erect and ascending, sometimes floating or creeping. Leaves in a basal rosette or cauline, alternate, simple or pinnate, often conspicuously emarginate and undulate. Inflorescence a simple or branched raceme. Flowers zygomorphic; sepals 4; petals 4, white, yellow or blue. Dispersal by seeds or vegetative fragments.

Natural habitat

riparian, shallow streams, littoral zone, mostly in flooded areas; rarely tolerates extended submersion

Additional comments

Some taxonomists consider the genus Rorippa to exclude Nasturtium. Here Rorippa includes Nasturtium, Neobeckia (a monotypic genus), and Armoracia aquatica (Eat.) Wieg. (=Rorippa aquatica). R. nasturtium-aquaticum (water cress) is commonly used as a vegetable in many countries. This has led to its wide-ranging introduction in many countries through deliberate plantings in natural waterways. Some authorities prefer the name Nasturtium officinale; both names are in equal usage in the literature.