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. 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. 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.