The Greek general Xenophon and the Persian King Xerxes ordered their soldiers to eat it to keep them healthy. Louis IX of France (St. Louis) found it so delightful that he placed it on a coat of arms. During the 14th-century, it had an important place on the menus at the courts of England’s Richard II and France’s Charles VI. And I just picked some up at my local grocery store.
Watercress, or Nasturtium officianale, is a member of the mustard family. It is native to Eurasia—the region of Asia Minor and the Mediterranean, more specifically. Despite the name, it is totally unrelated to the flower known as nasturtium (Tropaeolum majus), which is native to South and Central America and Mexico. (Though unrelated, which even a casual glance confirms, the two do share in common peppery-tasting leaves. It is my guess that the New World native was named nasturtium for the Old World herb that was equally peppery. In fact, nasturtiums, which are also used in salads, were sometimes called Indian cress.)
Watercress is famous for being somewhat ironic. It is peppery in taste, yet very refreshing. It was often used between courses at great meals, to cleanse the palate. Louis IX was enamored of it simply because, when overcome by thirst one day, with no water available, he was offered watercress, and found it so refreshing that he honored it by adding it, along with his royal fleur-de-lis, to the coat of arms of the French city of Vernon.
Watercress is not perhaps as widely used in the United States as it was–and in many places still is–in the Old World, but it may deserve a bit more attention, if for no other reason than its remarkable longevity as a popular salad green. In addition to health, the Greeks believed that eating watercress made one witty, while English herbalists of the 17th century recommended watercress soup to cleanse the blood in the spring or to help headaches.
Watercress is still considered a valuable spring tonic among herbalists, and watercress soup, in particular, is a popular item on spring menus across Europe. While it seems unlikely that watercress will add wit to your conversation, it is certainly healthful. A good source of vitamin C, it was a popular preventive for scurvy. Watercress also contains potassium, vitamin A, and several of the B vitamins. Anecdotally, many other medicinal traits have been attributed to the herb—but if all it does is give you an extra blast of vitamin C and spice up your menu, it doesn’t need to do more.
Because of its usefulness in preventing scurvy, watercress made the crossing to the New World very early, and it has now spread throughout North America, growing even in Alaska. It grows in cool, flowing streams, or in the muddy shallows bordering streams. However, the watercress one sees in the store is “farm raised.” (It is wise to obtain your watercress in this manner, because most of its composition is water, and it will contain whatever nasty things the water in which it is growing might contain, such as chemicals or germs from nearby animals.)
Because it easily takes root, you may only need to buy watercress occasionally. If you have more than you need, stick the remainder in a glass of water and put it in the sun. In a week or so, the stems will be sprouting little roots. Plant these newly sprouted cresses in rich soil, place in light shade, and keep well watered. In fact, to simulate natural growing conditions, you should set the pot in a dish of cool water, and change it daily. Harvest branchlets of watercress as needed, as garnishes or to add to sandwiches. Snipping the plant frequently actually encourages new growth. You can’t keep it going forever, but you can keep it going for quite a while–and there’s something wonderful about having more after a week than you had when you brought it home.