Watercress (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. The hollow stems of watercress are floating, and the leaves are pinnately compound. Small, white and green flowers are produced in clusters.