Nasturtium is the common garden flower whose edible flowers and leaves have a peppery taste. The name usually refers to garden nasturtium, Tropaeolum majus, a colorful ornamental plant with round leaves and yellow, orange, or red flowers.
Garden nasturtium is native to the Andes, from Bolivia north to Colombia, and is commonly grown as an annual or short-lived perennial. Its flowers are popular in salads because they add vivid color and a flavor often compared with watercress. The leaves are edible too, while the unripe seed pods can be pickled in vinegar and used as a caper substitute.
One frequent source of confusion is that garden nasturtium is not closely related to the botanical genus Nasturtium, which includes watercress. The peppery flavor in both plants comes from related mustard-oil chemistry, but they belong to different plant families. Nasturtiums are also valued in gardens because their trailing growth and bright flowers attract attention, while their edible foliage makes them useful ornamental food plants.