Watercress or yellowcress (''Nasturtium officinale'') is a species of aquatic flowering plant in the cabbage family Brassicaceae. Watercress is a rapidly growing perennial plant native to Europe and Asia. It is one of the oldest known leaf vegetables consumed by humans. Watercress and many of its relatives, such as

garden cress Cress (''Lepidium sativum''), sometimes referred to as garden cress (or curly cress) to distinguish it from Cress (disambiguation), similar plants also referred to as cress (from old Germanic ''cresso'' which means sharp, spicy), is a rather fas ...

, mustard, radish, and wasabi, are noteworthy for their piquant flavors. The hollow stems of watercress float in water. The leaf structure is

pinnately compound Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...

. Small, white, and green inflorescences are produced in clusters and are frequently visited by insects, especially hoverflies, such as ''

Eristalis ''Eristalis'' is a large genus of hoverflies, family Syrphidae, in the order Diptera. Several species are known as drone flies (or droneflies) because they bear a resemblance to honeybee drones. Drone flies and their relatives are fairly commo ...

'' flies.

Taxonomy

Watercress is listed in some sources as belonging to the genus '' Rorippa'', although molecular evidence shows those aquatic species with hollow stems are more closely related to ''

Cardamine ''Cardamine'' is a large genus of flowering plants in the mustard family, Brassicaceae, known as bittercresses and toothworts. It contains more than 200 species of annuals and perennials. Species in this genus can be found worldwide, except the ...

'' than ''Rorippa''. Despite the Latin name, watercress is not particularly closely related to the flowers popularly known as nasturtiums (''

Tropaeolum majus ''Tropaeolum majus'', the garden nasturtium, nasturtium, Indian cress or monks cress, is a species of flowering plant in the family Tropaeolaceae, originating in the Andes from Bolivia north to Colombia. An easily-grown annual or short-lived pere ...

''). ''T. majus'' belongs to the family

Tropaeolaceae ''Tropaeolum'' , commonly known as nasturtium (; literally "nose-twister" or "nose-tweaker"), is a genus of roughly 80 species of annual and perennial herbaceous flowering plants. It was named by Carl Linnaeus in his book ''Species Plantarum'' ...

, a sister taxon to the Brassicaceae within the order Brassicales.

Distribution

In some regions, watercress is regarded as a weed, in other regions as an aquatic vegetable or

herb In general use, herbs are a widely distributed and widespread group of plants, excluding vegetables and other plants consumed for macronutrients, with savory or aromatic properties that are used for flavoring and garnishing food, for medicinal ...

. Watercress has grown in many locations around the world. In the United Kingdom, watercress was first commercially cultivated in 1808 by the horticulturist William Bradbery along the River Ebbsfleet in Kent. Watercress is now grown in several counties of the United Kingdom, most notably Hampshire, Dorset, Wiltshire, and

Hertfordshire Hertfordshire ( or ; often abbreviated Herts) is one of the home counties in southern England. It borders Bedfordshire and Cambridgeshire to the north, Essex to the east, Greater London to the south, and Buckinghamshire to the west. For govern ...

. The town of Alresford, near

Winchester Winchester is a City status in the United Kingdom, cathedral city in Hampshire, England. The city lies at the heart of the wider City of Winchester, a local government Districts of England, district, at the western end of the South Downs Nation ...

, is considered to be the nation's watercress capital. It holds a Watercress Festival that brings in more than 15,000 visitors every year and a preserved steam railway line has been named after the local crop.

Uses

Watercress leaves, stems, and fruit can be eaten raw.

Tradition

Ancient Romans thought eating it would cure mental illness. Twelfth-century mystic Hildegard of Bingen thought eating it steamed and drinking the water would cure jaundice or fever. Watercress was eaten by Native Americans. Some Native Americans used it to treat kidney illnesses and constipation, and it was thought by some to be an aphrodisiac. Early

African Americans African Americans (also referred to as Black Americans and Afro-Americans) are an ethnic group consisting of Americans with partial or total ancestry from sub-Saharan Africa. The term "African American" generally denotes descendants of ens ...

used the plant as an

abortifacient An abortifacient ("that which will cause a miscarriage" from Latin: ''abortus'' "miscarriage" and '' faciens'' "making") is a substance that induces abortion. This is a nonspecific term which may refer to any number of substances or medications, ...

; it was believed to cause sterility as well.

Nutrition

The new tips of watercress leaves can be eaten raw or cooked, although caution should be used when collecting these in the wild because of parasites such as ''

giardia ''Giardia'' ( or ) is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada that colonise and reproduce in the small intestines of several vertebrates, causing the disease giardiasis. Their life cycle alternates between ...

''. Watercress is 95% water and has low contents of

carbohydrates In organic chemistry, a carbohydrate () is a biomolecule consisting of carbon (C), hydrogen (H) and oxygen (O) atoms, usually with a hydrogen–oxygen atom ratio of 2:1 (as in water) and thus with the empirical formula (where ''m'' may or may ...

, protein, fat, and

dietary fiber Dietary fiber (in British English fibre) or roughage is the portion of plant-derived food that cannot be completely broken down by human digestive enzymes. Dietary fibers are diverse in chemical composition, and can be grouped generally by the ...

. A 100-gram serving of raw watercress provides 11 calories, is particularly rich in vitamin K (238% of the Daily Value, DV), and contains significant amounts of vitamin A, vitamin C,

riboflavin Riboflavin, also known as vitamin B2, is a vitamin found in food and sold as a dietary supplement. It is essential to the formation of two major coenzymes, flavin mononucleotide and flavin adenine dinucleotide. These coenzymes are involved in ...

, vitamin B6, calcium, and manganese (table).

Phytochemicals and cooking

As a cruciferous vegetable, watercress contains isothiocyanates that are partly destroyed by boiling, while the content of

carotenoid Carotenoids (), also called tetraterpenoids, are yellow, orange, and red organic compound, organic pigments that are produced by plants and algae, as well as several bacteria, and Fungus, fungi. Carotenoids give the characteristic color to pumpki ...

s is slightly increased. Steaming or

microwave cooking A microwave oven (commonly referred to as a microwave) is an electric oven that heats and cooks food by exposing it to electromagnetic radiation in the microwave frequency range. This induces polar molecules in the food to rotate and produce th ...

retains these

phytochemical Phytochemicals are chemical compounds produced by plants, generally to help them resist fungi, bacteria and plant virus infections, and also consumption by insects and other animals. The name comes . Some phytochemicals have been used as poisons ...

Cultivation

Watercress cultivation is practical on both a large scale and a garden scale. Being semi-aquatic, watercress is well-suited to hydroponic cultivation, thriving best in water that is slightly

alkaline In chemistry, an alkali (; from ar, القلوي, al-qaly, lit=ashes of the saltwort) is a base (chemistry), basic, ionic compound, ionic salt (chemistry), salt of an alkali metal or an alkaline earth metal. An alkali can also be defined as ...

. It is frequently produced around the headwaters of chalk streams. In many local markets, the demand for hydroponically grown watercress exceeds supply, partly because cress

leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...

are unsuitable for distribution in dried form and can only be stored fresh for about 2-3 days. Also sold as sprouts, the edible shoots are harvested days after germination. If unharvested, watercress can grow to a height of .

Concerns

Watercress crops grown in the presence of manure can be an environment for parasites such as the liver fluke, '' Fasciola hepatica''. By inhibiting the cytochrome P450 enzyme CYP2E1, compounds in watercress may alter drug metabolism in individuals on certain medications such as chlorzoxazone. Due to its fast-growing nature and

invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...

status, ''Nasturtium officinale'' is prohibited in Illinois.

References

External links

''Rorippa nasturtium-aquaticum''
(ITIS)
GLANSIS Species Fact Sheet
{{Taxonbar, from=Q150452 Asian vegetables Nasturtium (genus) Freshwater plants Herbs Leaf vegetables Medicinal plants Perennial vegetables Flora of Europe Flora of temperate Asia