The Collaborative International Dictionary
Nasturtium \Nas*tur"tium\, n. [L. nasturtium, for nasitortium, fr. nasus nose + torquere, tortum, to twist, torture, in allusion to the causing one to make a wry face by its pungent taste. See Nose of the face, and Torture.]
(Bot.) A genus of cruciferous plants, having white or yellowish flowers, including several species of cress. They are found chiefly in wet or damp grounds, and have a pungent biting taste.
(Bot.) Any plant of the genus Trop[ae]olum, geraniaceous herbs, having mostly climbing stems, peltate leaves, and spurred flowers, and including the common Indian cress ( Trop[ae]olum majus), the canary-bird flower ( Trop[ae]olum peregrinum), and about thirty more species, all natives of South America. The whole plant has a warm pungent flavor, and the fleshy fruits are used as a substitute for capers, while the leaves and flowers are sometimes used in salads.
Wikipedia
Tropaeolum majus (garden nasturtium, Indian cress or monks cress) is a flowering plant in the family Tropaeolaceae, originating in the Andes from Bolivia north to Colombia. The species has become naturalized in parts of the United States ( California, New York, Pennsylvania, New Hampshire, Massachusetts and Connecticut). It is of cultivated, probably hybrid origin, with possible parent species including T. minus, T. moritzianum, T. peltophorum, and T. peregrinum. It is not closely related to the genus Nasturtium (which includes watercress).