Rorippa palustris is a species of flowering plant in the mustard family. It is widespread and native to parts of Africa, and much of Asia, Europe and Eurasia, North America and the Caribbean.<ref name=grin1/> It can also be found in other parts of the world as an introduced species and a common weed, for example, in Australia and South America.<ref name=grin1/> It is an adaptable plant which grows in many types of damp, wet, and aquatic habitat. It may be an annual, biennial, or perennial plant, and is variable in appearance as well.
It produces an erect stem, sometimes with branches, attaining a maximum height of just over one meter. The leaves are up to 30 centimeters long and have toothed to deeply lobed edges. The inflorescence is a raceme of mustardlike flowers with spoon-shaped yellow petals each a few millimeters in length. The fruit is a dehiscent and smoothly valved silicle, up to a centimeter long, and containing anywhere from 20 to 90 minute seeds.<ref name=jeps-key/>
In botanical literature, Rorippa palustris has been called by numerous common names (with variations). Some of them are listed here:
- bog marshcress<ref name=plants/>
- bog yellowcress<ref name=plants/>
- common yellowcress<ref name=plants/>
- marsh yellowcress<ref name=plants/> (or marsh yellow-cress)<ref name=BSBI07/>
- marshcress<ref name=plants/> (or marsh cress)<ref name=grin1/>
- yellow cress<ref name=grin1/>
- yellow watercress<ref name=plants/> (or yellow-watercress)<ref name=grin1/>
Rorippa palustris is native to, or naturalized across much of the globe.<ref name=grin1/>
- AFRICA:<ref name=grin1/> in Egypt and Ethiopia.
- ASIA and EURASIA:<ref name=grin1/> in Afghanistan; Bhutan; the Caucasus (in Armenia, Azerbaijan, Georgia, and Russia) and Ciscaucasia (in Dagestan); much of China and Taiwan; India (in the states of Assam, Bihar, Himachal Pradesh, Jammu and Kashmir, and West Bengal); Indonesia (in Papua province, Java, the Lesser Sunda, and Maluku Islands); Japan (in the prefectures of Hokkaido, Honshu, Kyushu, Shikoku, and the Ryukyu Islands); Kazakhstan; the Korean Peninsula; Kyrgyzstan; Mongolia; Pakistan; Papua New Guinea; eastern and western Siberia; Tajikistan; northeastern Turkey; Turkmenistan; Uzbekistan; and Yemen.
- EUROPE:<ref name=grin1/> in Albania; Austria; Belarus; Belgium; Bulgaria; Croatia; the Czech Republic; Denmark; Estonia; Finland; France; Germany; Hungary; Ireland; Italy; Latvia; Lithuania; the Republic of Macedonia; Moldova; the Netherlands; Norway; Poland; northern Portugal; Romania; Russia (Crimean Peninsula); Serbia; Slovakia; Slovenia; northern Spain; Sweden; Switzerland; Ukraine; and the United Kingdom.
- NORTH AMERICA:<ref name=plants/> in every province and territory (excluding Nunavut) of Canada; Puerto Rico; the District of Columbia and every state (excluding Hawaii) in the United States.
- The CARIBBEAN:<ref name=grin1/> in Cuba and Haiti.
- AUSTRALASIA:<ref name=grin1/> Australia.
- MEZO- and SOUTH AMERICA:<ref name=grin1/> in Argentina; Brazil; Chile; Ecuador; Panama; Peru; and Suriname.