Endive is closely related to and often confused with its cousin, chicory. They're both part of the same botanical family, Cichorium. There are three main varieties of endive: Belgian endive, curly endive and escarole. Belgian endive, also known as French endive and witloof (white leaf), is a small (about 6-inch-long), cigar-shaped head of cream-colored, tightly packed, slightly bitter leaves. It's grown in complete darkness to prevent it from turning green, using a labor-intensive growing technique known as blanching. Belgian endive is available from September through May, with a peak season from November through April. Buy crisp, firmly packed heads with pale, yellow-green tips. Belgian endives become bitter when exposed to light. They should be refrigerated, wrapped in a paper towel inside a plastic bag, for no more than a day. They can be served cold as part of a salad, or cooked by braising or baking. Curly endive, often mistakenly called chicory in the United States, grows in loose heads of lacy, green-rimmed outer leaves that curl at the tips. The off-white center leaves form a compact heart. The leaves of the curly endive have a prickly texture and slightly bitter taste. Escarole has broad, slightly curved, pale green leaves with a milder flavor than either Belgian or curly endive. Both curly endive and escarole are available year-round, with the peak season from June through October. They should be selected for their fresh, crisp texture; avoid heads with discoloration or insect damage. Store curly endive and escarole, tightly wrapped, in the refrigerator for up to 3 days. They're both used mainly in salads, but can also be briefly cooked and eaten as a vegetable or in soups.