The watermelon is one of two broad categories of melon, the other being muskmelon. The watermelon is by some considered the less sophisticated of the two because it lacks flavor complexity and has a watery texture (it is more than 90 percent water).
More than 1200 varieties of watermelon are grown worldwide. It averages 15 to 35 pounds (6 to 16 kilograms) but may be much smaller or larger, depending on the variety. The most common varieties have a sweet, red flesh with small black seeds, and a variegated or striped, two-tone green or gray-green rind. The rind should be firm and just barely yield to pressure. Avoid buying melons that have soft spots on the rind.
Watermelon does not contain any fat or cholesterol, is high in fiber and vitamins A & C and is a good source of potassium.