Believed to have originated in either India or Thailand, the cucumber has been cultivated for thousands of years. This long, cylindrical, green-skinned fruit of the gourd family has edible seeds surrounded by a mild, crisp flesh. The thin skin, unless waxed, does not require peeling. Cucumbers are usually eaten raw, as in salads. The smaller cucumber varieties are used for pickles. As a cucumber matures, the seeds grow larger and more bitter. Therefore, the seeds of an older cucumber should be removed before it's used. The more expensive English (or hothouse) cucumber can grow up to 2 feet long and is virtually seedless and purportedly burpless. They're marketed shrink-wrapped in plastic. Cucumbers are available year-round, with the peak crop from May to August. Choose firm fruit with smooth, brightly colored skins; avoid those with shriveled or soft spots. Store whole cucumbers, unwashed, in a plastic bag in the refrigerator up to 10 days. Wash thoroughly just before using. Cut cucumbers can be refrigerated, tightly wrapped, for up to 5 days.