WATERCRESS

Family: Brassicaceae (Cruciferae), Nasturtium officinale R. Br.

Source: Simon, J.E., A.F. Chadwick and L.E. Craker. 1984. Herbs: An Indexed Bibliography. 1971-1980. The Scientific Literature on Selected Herbs, and Aromatic and Medicinal Plants of the Temperate Zone. Archon Books, 770 pp., Hamden, CT.

Watercress, Nasturtium officinale R. Br., is an aquatic perennial herb native to Europe and naturalized in the United States. Also known as green watercress and previously classified as Rorippa Nasturtiumaquaticum (L.) Hayak, this succulent, glabrous herb reproduces vegetatively forming roots at nodes. The plant is characterized by 0.3 to 1 meter long floating and ascending stems, green, fleshy leaflets, and small white flowers (14.1-4).

The reported life zone of watercress is 6 to 27°C with an annual precipitation of 0.3 to 4.2 meters and a soil pH of 4.3 to 8.3 (4.1-31). The species is found in areas of running water adjacent to springs and riverbanks or on wet soil. The plant thrives in full sunlight and cool water. Although susceptible to frost injury in the autumn and spring, the submerged portion of the plant will survive if the water remains unfrozen.

Careful attention to providing an adequate and good-quality water supply is essential for successful commercial production. Plants are generally grown in water tanks or beds having soil bottoms and moving water. Beds of watercress can be maintained for about ten years without resowing or replanting and require about one month to reach a harvestable stage after a previous harvest (14.1-1). Usually a number of beds are maintained by growers to provide a continuous supply of the herb.

Fresh leaves of watercress are used as salad greens and as a garnish. The leaves can be steamed and eaten as a vegetable. Watercress is nutritious, being high in minerals, proteins, and vitamins.

As a medicinal plant, watercress has been traditionally considered a diuretic, expectorant, purgative, stimulant, stomachic, and tonic. It has also been used as a remedy against anemia, eczema, kidney and liver disorders, tuberculosis, boils, warts, and tumors (14.1-14).

Nasturtium microphyllum Boenn. ex Rchb., an occasionally used salad plant formerly known as Rorippa microphylla (Boenn. ex Rchb.) Hyl., both resembles and hybridizes with watercress. The plant is more frost hardy than watercress and turns purplish brown in autumn (14.1-12).

[Note: References listed above in parentheses can be found in full in the original reference].

Last modified 6-Dec-1997