Watermelon Information

Watermelon (Citrullus lanatus, Family Cucurbitaceae) is both a fruit and a vegetable and plant of a vine-like (climber and trailer) herb originally from southern Africa and one of the most common type of melon. This flowering plant produces a special type of fruit known by botanists as a pepo, which has a thick rind (exocarp) and fleshy center (mesocarp and endocarp); pepos are derived from an inferior ovary and are characteristic of the Cucurbitaceae. The watermelon fruit, loosely considered a type of melon (although not in the genus Cucumis), has a smooth exterior rind (green and yellow) and a juicy, sweet, usually red or yellow, but sometimes orange, interior flesh. The flesh consists of highly developed placental tissue within the fruit.

David Livingstone, an explorer of Africa, described watermelon as abundant in the Kalahari Desert, where it is believed to have originated.

It is not known when the plant was first cultivated, but Zohary and Hopf note evidence of its cultivation in the Nile Valley from at least as early as the second millennium BC. By the 10th century AD, watermelons were being cultivated in China, which is today the world's single largest watermelon producer. By the 13th century, Moorish invaders had introduced the fruit to Europe.

Until the 1940s, however, it was hard to find watermelons in good condition at grocery stores. Melon lovers had to grow their own, which tended not to keep for long, purchase them from local grocers supplied by truck farmers, or purchase them from roadside produce stands. Now they can be found in most any local grocery store, and if preferred in slices or whole, with seeds or without.

Although so-called "seedless" watermelons have far fewer seeds than the seeded varieties, they generally contain at least a few soft, pale seeds. They are the product of crossing a female tetraploid plant (itself the product of genetic manipulation, using colchicine) with diploid pollen. The resulting triploid plant is sterile, but will produce the seedless fruit if pollenized by a diploid plant. For this reason, commercially available seedless watermelon seeds actually contain two varieties of seeds; that of the triploid seedless plant itself (recognizable because the seed is larger), and the diploid plant which is needed to pollenize the triploid. Unless both plant types are grown in the same vicinity, no seedless fruit will result.

A one-cup serving of watermelon will provide around 48 calories. Watermelon is an excellent source of vitamin C and vitamin A, with one serving containing 14.59 mg of vitamin C and 556.32 IU of vitamin A. Watermelon also provides significant amounts of vitamin B6 and vitamin B1, as well as the minerals potassium and magnesium. Pink watermelon is also a source of the potent carotenoid antioxidant, lycopene. Watermelon rinds are also edible, and sometimes used as a vegetable. In China, they are stir-fried, stewed, or more often pickled. When stir-fried, the de-skinned and de-fruited rind is cooked with olive oil, garlic, chili peppers, scallions, sugar and rum (and provides a great way to utilize the whole watermelon). Pickled watermelon rind is also widespread in Russia, Ukraine, and Romania. Watermelon seeds are rich in fat and protein, and are widely eaten as a snack, added to other dishes, or used as an oilseed. Specialized varieties are grown which have little watery flesh but concentrate their energy into seed production. In China watermelon seeds are one of the most common snack foods, popular especially with women, competing with sunflower seeds, and sold roasted and seasoned. In West Africa, they are pressed for oil, and are popular in egusi soup and other dishes. There can be some confusion between seed-specialized watermelon varieties and the colocynth, a closely-related species with which they share many characteristics, uses, and similar or identical names. Watermelon is 92 percent water by weight, the highest percentage of any fruit.