Watercresses are fast-growing, aquatic or semi-aquatic, perennial plants native to Europe and Asia, and one of the oldest known leaf vegetables consumed by humans. They are members of the family Brassicaceae, botanically related to garden cress, mustard and radish a__ all noteworthy for a peppery, tangy flavour.The hollow stems of watercress are floating, and the leaves are pinnately compound. Small, white and green flowers are produced in clusters.Nasturtium nasturtium-aquaticum (nomenclaturally invalid) and Sisymbrium nasturtium-aquaticum L. are synonyms of N. officinale. Nasturtium officinale var microphyllum (Boenn. ex Reich.) Thellung is a synonym of N. microphyllum (ITIS, 2004).
Contributions by Ralphrye, Plautus satire, and AtticusX.