Watercress

For the vegetable sometimes called Chinese watercress, see Ipomoea aquatica. For the railway line, see Watercress Line.

Watercress Nasturtium officinale
Nasturtium officinale
Scientific classification
Kingdom:	Plantae
(unranked):	Angiosperms
(unranked):	Eudicots
(unranked):	Rosids
Order:	Brassicales
Family:	Brassicaceae
Genus:	Nasturtium
Species:	N. officinale
Binomial name
Nasturtium officinale W.T. Aiton
Synonyms
Nasturtium nasturtium-aquaticum (L.) H. Karst. Rorippa nasturtium-aquaticum (L.) Hayek Sisymbrium nasturtium-aquaticum L.

Watercress, with the botanical name Nasturtium officinale, is a fast-growing, aquatic or semi-aquatic, perennial plant native to Europe and Asia, and one of the oldest known leaf vegetables consumed by humans. It is a member of the family Brassicaceae, botanically related to garden cress, mustard and radish — all noteworthy for a peppery, tangy flavour.

Hey tj perry , and the leaves are pinnately compound. Small, white and green flowers are produced in clusters.

Taxonomy

Nasturtium nasturtium-aquaticum (nomenclaturally invalid) and Sisymbrium nasturtium-aquaticum L. are synonyms of N. officinale. Watercress is also listed in some sources as belonging to the genus Rorippa, although molecular evidence shows the aquatic species with hollow stems are more closely related to Cardamine than Rorippa. Despite the Latin name, watercress is not closely related to the flowers popularly known as nasturtiums (Tropaeolum majus).

Cultivation

Watercress beds in Warnford, Hampshire.

Cultivation of watercress 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. 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 are unsuitable for distribution in dried form, and can only be stored fresh for a short period.

Watercress can be sold in supermarkets in sealed plastic bags, containing a little moisture and lightly pressurised to prevent crushing of contents. This has allowed national availability with a once-purchased storage life of one to two days in chilled/refrigerated storage.

Also sold as sprouts, the edible shoots are harvested days after germination. If unharvested, watercress can grow to a height of 50–120 centimetres (1.6–3.9 ft). Like many plants in this family, the foliage of watercress becomes bitter when the plants begin producing flowers.

Distribution

In some regions, watercress is regarded as a weed, in other regions as an aquatic vegetable or herb. Watercress has been 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 a number of counties of the United Kingdom, most notably Hertfordshire, Hampshire, Wiltshire and Dorset. The town of Alresford, near Winchester, 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. In recent years, watercress has become more widely available in the UK, at least in the southeast; it is stocked pre-packed in some supermarkets, as well as fresh by the bunch at farmers' markets and greengrocers.

In the United States in the 1940s, Huntsville, Alabama was locally known as the "watercress capital of the world". Today, Oviedo, Florida in the United States is known by that title, while Alresford in England is considered to be that nation's watercress capital.

Health benefits

Watercress, raw

Nutritional value per 100 g (3.5 oz)
Energy	46 kJ (11 kcal)
Carbohydrates	1.29 g
Sugars	0.2 g
Dietary fiber	0.5 g
Fat	0.1 g
Protein	2.3 g
Vitamins and minerals Vitamins Quantity %DV† Vitamin A equiv. beta-Carotene lutein zeaxanthin 18% 160 μg 18% 1914 μg 5767 μg Thiamine (B1) 8% 0.09 mg Riboflavin (B2) 9% 0.12 mg Pantothenic acid (B5) 6% 0.31 mg Vitamin B6 8% 0.129 mg Folate (B9) 2% 9 μg Vitamin C 48% 43 mg Vitamin E 7% 1 mg Vitamin K 208% 250 μg Minerals Quantity %DV† Calcium 9% 120 mg Iron 1% 0.2 mg Magnesium 5% 21 mg Manganese 11% 0.244 mg Phosphorus 5% 60 mg Potassium 11% 330 mg Sodium 2% 41 mg
Link to USDA Database entry
†Percentages estimated using US recommendations for adults, except for potassium, which is estimated based on expert recommendation from the National Academies.

Watercress contains significant amounts of iron, calcium, iodine, and folic acid, in addition to vitamins A and C. Because it is relatively rich in Vitamin C, watercress was suggested (among other plants) by English military surgeon John Woodall (1570–1643) as a remedy for scurvy.

Many benefits from eating watercress are claimed, such as that it acts as a stimulant, a source of phytochemicals and antioxidants, a diuretic, an expectorant, and a digestive aid. It also appears to have antiangiogenic cancer-suppressing properties; it is widely believed to help defend against lung cancer. A 2010 study conducted by the University of Southampton found that consumption of watercress may also inhibit the growth of breast cancer. The content of phenethyl isothiocyanate (PEITC) in watercress inhibits HIF, which can inhibit angiogenesis.

Watercress is mentioned in the Talmud as being able to stop bleeding, when mixed with vinegar.

Side effects

Watercress crops grown in the presence of manure can be a haven for parasites such as the liver fluke Fasciola hepatica. Watercress is a known inhibitor of the cytochrome P450 CYP2E1, which may result in altered drug metabolism for individuals on certain medications such as chlorzoxazone.

See also

• Fools watercress — Apium nodiflorum

External links

• Rorippa nasturtium-aquaticum (ITIS)
• GLANSIS Species Fact Sheet