So familiar to the American summer food scene—what would July 4th be without it? -- it's easy to forget that watermelons were a staple of the ancient world long before they arrived on these shores, brought here by 17th century slave traders.

A vine native to Africa, watermelon, with its 90% water content, proved to be a valuable supply of portable water, prompting its popularity to spread. Six thousand years ago, Egyptian artists portrayed it on the walls of tombs, and it was later cultivated in the Middle East and in Russia, where they make beer out of watermelon juice. The Moors introduced watermelon to Europe after they invaded Spain.

In America, watermelon achieved instant popularity with both new settlers and Native Americans. Thrifty pioneer women even made pickles from the rind. Today, Americans consume about 3 billion lb. annually, choosing from the more than 100 varieties available.

Chefs use watermelon to show off its color and delicate flavor. Its high water content makes it a natural for sorbets, granitas, and refreshing drinks. As a cocktail, it's often paired with tequila in margaritas. And dishes like watermelon, goat cheese, and watercress salad benefit from its bright hue and texture, as do relishes, salsas, soups, smoothies, and slaws. Watermelon contains only 25 calories per 1/2-cup serving, making it a popular choice for light menus.

Botanically a vegetable, with the Latin name, Citrullus vulagris, watermelon is a cousin to the cucumber. It's a source of vitamins A and C, as well as the mineral potassium. The red varieties contain the anti- oxidant lycopene, in amounts second only to tomatoes. Size ranges from 7-100 lb. The record stands at 225 lb. for a melon grown in Oklahoma.

For foodservice, watermelons come in 35-85 lb. cartons. Peak season is mid-June to late August, but watermelons are available May through September. Although grown all over the country, the South, with its longer growing season, offers the most favorable environment.

Ripe melons should be firm, heavy for their size and respond with a deep tone when thumped. The rind should be dull and waxy. A yellowish underside indicates the melon touched the ground after drooping from the vine, which is a good indication of ripeness. Watermelons don't ripen after harvesting.

Store uncut for up two weeks at room temperature. Keep away from ethylene gas-producing fruits like apples and bananas. Once cut, wrap the melon tightly and refrigerate.

Besides the standard large, oblong-shaped watermelon, several other varieties are now being marketed:

Sugar Baby: The name comes from its sweetness, but this baby can weigh up to 9 lb. It usually fits in the home refrigerator, hence its other name -- Icebox Melon. It has a jade-green rind and bright crimson flesh.

Picnic: A large, round or oblong melon with a light to dark green rind, with or without stripes.

Seedless: Oval to round, with the rind light green and dark green stripes. Tiny white edible seeds fleck the red or yellow flesh.

Yellow: Oblong to long. The light green rind has mottled stripes. The flesh is yellow to bright orange.

Pureheart: One of the latest innovations in the world of seedless watermelons. Described as a personal-sized watermelon, it weighs between 3-6 lb., has deep crimson flesh, and a thin rind.