Review: 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. Fresh watermelon may be eaten in a variety of ways and is also often used to flavor summer drinks and smoothies.A one-cup serving of watermelon will provide around 48 Calories. Watermelon is an excellent source of vitamin C and vitamin A. Watermelon rinds are also edible, and sometimes used as a vegetable.