Watercress

Watercress (Nasturtium officinale; also known as Rorippa nasturtium-aquaticum) is a fast-growing aquatic flowering plant in the Brassicaceae family. It is cultivated for its peppery-tasting green leaves and stems. Native to Europe and western Asia, it typically grows in clear, shallow, running water and has been naturalized in many regions.

Description and habitat: Watercress forms upright, branching stems anchored by a shallow root system. Leaves are small and pinnate, with rounded leaflets. White flowers appear in dense racemes in late spring and early summer. The plant thrives in cool, temperate climates and in nutrient-rich, continually refreshed water.

Cultivation and production: In cultivation, watercress is grown in flowing water or hydroponic systems that supply clean water and strong aeration. Plants are harvested by cutting the tops above the waterline, enabling regrowth. Commercial operations emphasize water quality, sanitation, and disease control to maintain safety.

Uses and nutrition: Watercress is popular raw in salads and sandwiches and can be cooked in soups and garnishes. It is low in calories but rich in vitamins, especially vitamin K and vitamin C, and provides manganese and calcium. Glucosinolates give its characteristic peppery flavor.

Safety and historic notes: Because it grows in water, proper washing is important to remove sediment and potential pathogens. Large intakes of vitamin K can affect anticoagulant medications, and watercress from polluted sources should be avoided.

Taxonomy and common names: Watercress has a long culinary history in Europe and Asia and is among the oldest cultivated leafy greens. Taxonomic assignments vary, with Nasturtium officinale and Rorippa nasturtium-aquaticum used as synonyms. It should not be confused with the ornamental nasturtium (Tropaeolum).