The watermelon (Citrullus lanatus) is a low growing vine that originated in southern Africa. The watermelon is an ancient fruit -- the Egyptians were harvesting them 5,000 years ago, and today, watermelons grow from the United States to China, Russia, and Japan.
Watermelons are typically oblong, with a hard, greenish rind and pink flesh, though they can be grown in any shape, and have orangish or yellow flesh. They range in weight, but the most common varieties weigh between 15 and 30 pounds. The heaviest watermelon on record weighed 262 pounds. It is important to look for the creamy yellow-beige patch on one side of the watermelon, as this is a good indicator that it was fully ripened on the vine. Watermelons must be hand harvested, as they are relatively fragile.
As its name suggests, a watermelon is 92% water, by weight, with 6% sugar. They have a soft, slightly grainy flesh that is easily juiced. Watermelon juice is fairly sweet, so it is used in liquados, Mexican fruit juice based drinks. The rind is also edible, though it is strongly bitter, and is typically stir-fried in Chinese cooking, or pickled in the American south to make it palatable.