logo of PROTA Prota 2: Vegetables/L้gumes
Record display


Nasturtium officinale R.Br.

Family
Brassicaceae (Cruciferae)
Chromosome number
2n = 32
Synonyms
Rorippa nasturtium-aquaticum (L.) Hayek (1905).
Vernacular names
Watercress (En). Cresson, cresson de fontaine (Fr). Agriใo de แgua, agriใo das fontes (Po).
Origin and geographic distribution
Watercress is native in Europe and western Asia, and possibly also in the highland regions of Ethiopia. It has been introduced in many African regions, and is locally naturalized in mainland Africa, Madagascar and other Indian Ocean islands, mainly in mountainous regions. It has been introduced into many other tropical and temperate regions.
Uses
Young shoots with leaves are used as a pungent garnish and eaten raw in salads. Watercress is also eaten as a cooked vegetable or made into watercress soups. In Africa it is mainly eaten by expatriate communities. Watercress has a long history as a medicinal plant, used to prevent scurvy. In the United States and Europe it is now a health food used against a wide range of ailments such as itching of the skin, as antiscorbutic stimulant and as a laxative.
Production and international trade
Watercress is locally important in the Western world, but few statistics on production or trade are available. Annual production in the United Kingdom is about 2500 t, but declining. In France, the production is about 10,000 t. In Africa it is cultivated on a small scale throughout the continent.
Properties
The nutritional composition of watercress per 100 g edible portion (large stalks removed, 62% as purchased) is: water 92.5 g, energy 92 kJ (22 kcal), protein 3.0 g, fat 1.0 g, carbohydrate 0.4 g, dietary fibre 1.5 g, Ca 170 mg, Mg 15 mg, P 52 mg, Fe 2.2 mg, Zn 0.7 mg, carotene 2520 μg, thiamin 0.16 mg, riboflavin 0.06 mg, niacin 0.3 mg, ascorbic acid 62 mg (Holland, B., Unwin, I.D. & Buss, D.H., 1991).
Watercress yields a pungent volatile oil containing glucosinolates. Some of these compounds produce anti-carcinogenic compounds on hydrolysis, e.g. phenethyl isothiocyanate, which showed protection against cancers associated with tobacco-specific carcinogens. Flavonols and megastigmanes were isolated showing histamine release inhibiting activity.
Description
Perennial creeping or floating, glabrous herb; stem up to 1 m long, hollow, juicy, much branched, with roots on stem nodes. Leaves alternate, up to 10 cm long, without stipules, stalked, pinnate; lateral leaflets in 2–9 pairs, sessile, nearly circular to elliptical or obovate, entire to slightly toothed, terminal leaflet usually larger. Inflorescence a terminal raceme c. 10 cm long, without bracts. Flowers bisexual, 4-merous; sepals c. 2 mm long; petals obovate, c. 4 mm long, white; stamens 6, free, with yellow anthers; ovary superior, 2-celled, style simple. Fruit a broadly linear silique 1–2 cm ื 2–3 mm, with many seeds in 2 rows in each cell. Seeds spherical, dark red-brown, reticulate. Seedling with epigeal germination; hypocotyl 7–8 mm long, epicotyl 2–3 mm long; cotyledons stalked, circular, 2–4 mm long, leafy.
Other botanical information
Nasturtium comprises 5 species. It is often included in the larger genus Rorippa, but molecular data, combined with morphological differences, support the separation from Rorippa and show that Nasturtium is most closely related to Cardamine.
Nasturtium microphyllum (Boenn.) Rchb. is closely related to Nasturtium officinale; it differs in its slightly larger flowers and more slender but longer fruits with seeds in a single row per cell. It is an allotetraploid with 2n = 64. It occurs naturalized in Africa in similar habitats as Nasturtium officinale, and is sometimes also cultivated as watercress.
Growth and development
Soon after planting stem cuttings develop roots on the nodes. The strongly branching plants may develop a thick mass of vegetation. In equatorial areas watercress seldom flowers. Under long-day conditions of over 13 hours, watercress flowers profusely when the flow of water becomes stagnant and especially when the water level becomes shallow and the land starts drying. It is self compatible. Watercress can be harvested for several years, but diseases and weeds may necessitate new planting.
Ecology
Watercress occurs naturally along running water and grows floating in shallow water. Shallow ponds can rapidly become covered and the species is sometimes considered an inoffensive weed. It is easy to establish a watercress crop wherever conditions are cool and wet. It grows in East Africa at elevations above 500 m. It requires running water for vigorous growth and high yield of tender and sweet shoots. When there is no longer running water, plants become bitter and are no longer suitable for consumption. At higher latitudes in the summer abundant flowering will impede the harvest. Watercress likes sandy or gravelly soils and is rather common in limestone areas, preferring neutral to slightly alkaline water with pH 6.5–7.5. The water should be rich in minerals and contain 1–4 ppm of nitrate. The water temperature should not exceed 26ฐC. It can withstand light frost (–2ฐC). Watercress tolerates polluted soil and water, contaminated by heavy metals, but these can be found as residues in the harvested product. The reduced water current velocities due to watercress appear to be important for the distribution of small invertebrates, creating a variety of living conditions in the water column. Watercress can harbour small snails (Lymnaea truncatula and Bulinus spp.) that host river flukes (Fasciola hepatica) and bilharzia parasites (Schistosoma haematobium, Schistosoma intercalatum); its cultivation in uncontrolled water is therefore not recommended, and in case of doubt it is better to cook watercress before consumption. In France, it is the only vegetable subjected to an obligatory veterinarian check. A watercress habitat provides cover and abundant food supply for fish.
Management
Once the crop has been established, only limited attention is given apart from occasional weeding. Most important is the control of water flow, ensuring that the water current does not become too strong. When the water source dries up during the dry season, it is important to irrigate sufficiently to keep the crop alive, allowing an adequate supply of planting material for the next season. Farmers in Arusha (Tanzania) divert local streams to flood small plots of land covered with watercress. Watercress requires plenty of phosphate and nitrate and these should be applied if the nutrient content of the plant bed is low.
Propagation and planting
Watercress is usually reproduced from stem cuttings. Reproduction by seed is sometimes practised in temperate areas. Cuttings 10–20 cm long are planted in mud beds at a spacing of 20 cm ื 20 cm with frequent irrigation or continuous running water. They root easily in moist sand.
Diseases and pests
Diseases are rarely a problem in watercress. In Asia the crop may be affected by a virus which spreads when using cuttings only. To overcome this problem seedlings should be planted rather than using cuttings. The seed should be collected from vigorous plants that are free from diseases. In the Caribbean region Cercospora nasturtii is recorded as the main disease. Aster yellows transmitted by leafhoppers can be a problem, e.g. in Hawaii. Flea beetles, aphids and caterpillars could affect the crop but with an adequate flow of water they are usually not a problem, especially if farmers can submerge the crop as a control measure.
Harvesting
Watercress can be harvested 6–8 weeks after planting and subsequent harvests can be made every 3 weeks for more than a year.
Yield
Farmers may collect up to 2 kg/m2 from the first harvest and up to 1 kg/m2 from subsequent harvests, but the yield will decline rapidly as the crop senesces, the flow of water reduces or nutrient contents diminish. An annual yield of up to 50 t/ha is easily possible.
Handling after harvest
Harvested shoots are tied in bunches and yellow leaves are removed before dispatch to the market. Watercress is perishable and can only be stored at low temperatures and close to 100% relative humidity.
Genetic resources
No germplasm collections are known in Africa, but the diversity in naturalized populations is significant.
Breeding
Little breeding work on watercress has been done, although some seed catalogues list watercress. In Africa people virtually always use cuttings rather than seeds and no plant breeding activities take place at present.
Prospects
The demand for watercress in Africa is becoming lower as the population of European origin declines. Local demand is likely to be satisfied by collection from wild and naturalized Nasturtium and Rorippa species.
Major references
• Al-Shehbaz, I.A. & Price, R.A., 1998. Delimitation of the genus Nasturtium (Brassicaceae). Novon 8(2): 124–126.
• Jonsell, B., 1982. Cruciferae. In: Polhill, R.M. (Editor). Flora of Tropical East Africa. A.A. Balkema, Rotterdam, Netherlands. pp. 15–17.
• Jonsell, B., 2000. Brassicaceae (Cruciferae). In: Edwards, S., Mesfin Tadesse, Demissew Sebsebe & Hedberg, I. (Editors). Flora of Ethiopia and Eritrea. Volume 2, part 1. Magnoliaceae to Flacourtiaceae. The National Herbarium, Addis Ababa University, Addis Ababa, Ethiopia and Department of Systematic Botany, Uppsala University, Uppsala, Sweden. pp. 121–154.
• Messiaen, C.-M., 1989. Le potager tropical. 2nd Edition. Presses Universitaires de France, Paris, France. 580 pp.
• Palaniswamy, U.R., McAvoy, R.J., Bible, B.B. & Stuart, J.D., 2003. Ontogenic variations of ascorbic acid and phenethyl isothiocyanate concentrations in watercress (Nasturtium officinale R.Br.) leaves. Journal of Agricultural and Food Chemistry 51(18): 5504–5509.
• Rahmansyah, M., 1993. Rorippa Scop. In: Siemonsma, J.S. & Kasem Piluek (Editors). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 239–241.
• Rothwell, S.D. & Robinson, L.W., 1986. Cold acclimatisation potential of watercress (Rorippa nasturtium-aquaticum) in relation to growing season and nutrient status. Journal of Horticultural Science 61(3): 373–378.
• Schippers, R.R., 2000. African indigenous vegetables. An overview of the cultivated species. Natural Resources Institute/ACP-EU Technical Centre for Agricultural and Rural Cooperation, Chatham, United Kingdom. 214 pp.
Other references
• Abe, K., Ozaki, Y. & Kihou, N., 1993. Use of higher plants and bed filter materials for domestic wastewater treatment in relation to resource recycling. Soil Science and Plant Nutrition 39(2): 257–267.
• Agnew, A.D.Q. & Agnew, S., 1994. Upland Kenya wild flowers: a flora of the ferns and herbaceous flowering plants of upland Kenya. 2nd Edition. East Africa Natural History Society, Nairobi, Kenya. 374 pp.
• Andrews, F.W., 1950. The flowering plants of the Anglo-Egyptian Sudan. Volume 1. Buncle, Arbroath, United Kingdom. 237 pp.
• Cumbus, I.P., Robinson, L.W. & Clare, R.G., 1980. Mineral nutrient availability in watercress (Rorippa nasturtium-aquaticum) bed substrates. Aquatic Botany 9(4): 343–350.
• Fassett, N.C., 1957. A manual of aquatic plants. University of Wisconsin Press, Madison, United States. 405 pp.
• Getahun, S.M. & Chung, F.L., 1999. Conversion of glucosinolates to isothiocyanates in humans after ingestion of cooked watercress. Cancer Epidemiology, Biomarkers & Prevention 8: 447–451.
• Gregg, W.W. & Rose, F.L., 1985. Influence of aquatic macrophyte on invertebrate community structure, guild structure, and micro-distribution in streams. Hydrobiologia 128(1): 45–46.
• Holland, B., Unwin, I.D. & Buss, D.H., 1991. Vegetables, herbs and spices. The fifth supplement to McCance & Widdowson’s The Composition of Foods. 4th Edition. Royal Society of Chemistry, Cambridge, United Kingdom. 163 pp.
• Kaskey, J.B. & Tindall, D.R., 1980. Physiological reports of growth and heteroblastic development of Nasturtium officinale under natural conditions. Aquatic Botany 7(3): 209–230.
• McHugh, J.J., Fukuda, S.K. & Takeda, K.Y., 1987. Hawaii watercress production. Research Extention Series, No 88, Hawaii Institute of Tropical Agriculture and Human Resources, Honolulu, United States. 10 pp.
• Robyns, W. & Boutique, R., 1951. Cruciferae. In: Robyns, W., Staner, P., Demaret, F., Germain, R., Gilbert, G., Hauman, L., Hom่s, M., Jurion, F., Lebrun, J., Vanden Abeele, M. & Boutique, R. (Editors). Flore du Congo belge et du Ruanda-Urundi. Spermatophytes. Volume 2. Institut National pour l’ษtude Agronomique du Congo belge, Brussels, Belgium. pp. 522–544.
• Rose, P., Faulkner, K., Williamson, G. & Mithen, R., 2000. 7-methylsulfinylheptyl and 8 methylsulfinyloctyl isothiocynanates from watercress are potent inducers of phase II enzymes. Carcinogenesis 21(11): 1983–1988.
• Sheridan, G.E.C., Claxton, J.R., Clarkson, J.M. & Blakesley, D., 2001. Genetic diversity within commercial populations of watercress (Rorippa nasturtium-aquaticum), and between allied Brassicaceae inferred from RAPD-PCR. Euphytica 122: 319–325.
• Singh, A.V., Dong Xiao, Lew, K.L., Dhir, R. & Singh, S.V., 2004. Sulforaphane induces caspase mediated apoptosis in cultured PC-3 human prostate cancer cells and retards growth of PC-3 xenografts in vivo. Carcinogenesis 25(1): 83–90.
• Spence, R.M.M., Tucnot, O.G., Baker, E.A. & Holoway, P.J., 1983. Compounds associated with the surface lipid layer of watercress (Rorippa nasturtium-aquaticum). Phytochemistry 22(8): 1753–1756.
• Tindall, H.D., 1968. Commercial vegetable growing. Oxford University Press, United Kingdom. 300 pp.
• Wong, M.H., 1985. Toxic effect of iron ore tailings and the response of watercress from tailings at high concentration of iron, zinc and manganese. Environmental Pollution, series A, Ecology and Biology 38(2): 129–140.
Sources of illustration
• Rahmansyah, M., 1993. Rorippa Scop. In: Siemonsma, J.S. & Kasem Piluek (Editors). Plant Resources of South-East Asia No 8. Vegetables. Pudoc Scientific Publishers, Wageningen, Netherlands. pp. 239–241.
Author(s)
• R.R. Schippers
De Boeier 7, 3742 GD Baarn, Netherlands


Editors
• G.J.H. Grubben
Prins Hendriklaan 24, 1401 AT Bussum, Netherlands
• O.A. Denton
National Horticultural Research Institute, P.M.B. 5432, Idi-Ishin, Ibadan, Nigeria
Associate Editors
• C.-M. Messiaen
Bat. B 3, R้sidence La Guirlande, 75, rue de Fontcarrade, 34070 Montpellier, France
• R.R. Schippers
De Boeier 7, 3742 GD Baarn, Netherlands
General editors
• R.H.M.J. Lemmens
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
• L.P.A. Oyen
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands
Illustrator
• PROSEA
PROSEA Network Office, Herbarium Bogoriense, P.O. Box 234, Bogor 16122, Indonesia
Photo Editor
• E. Boer
PROTA Network Office Europe, Wageningen University, P.O. Box 341, 6700 AH Wageningen, Netherlands

Correct citation of this article:
Schippers, R.R., 2004. Nasturtium officinale R.Br. In: Grubben, G.J.H. & Denton, O.A. (Editors). PROTA 2: Vegetables/L้gumes. [CD-Rom]. PROTA, Wageningen, Netherlands.
Distribution Map planted and naturalized


flowering and fruiting branch.
Source: PROSEA



flowering plant


crop grown along watercourse


plants in the field


weed