Lettuce

There are hundreds of varieties of lettuce grown with differing harvest times. In the US these varieties fall into 4 main categories (each covering many varieties): butterhead, crisphead, leaf and romaine. Butterhead has small, round, loosely formed heads with soft, buttery-textured leaves ranging from pale green on the outer leaves to a pale yellow-green on the inner leaves. The flavor is sweet and succulent. Crisphead lettuce comes in large, round, tightly packed heads of pale green leaves. Though crisp, succulent and wilt-resistant, all crispheads have a rather neutral flavor. Romaine lettuce grows in a long head of sturdy leaves which have a firm rib down their centers. Varieties include green, red and baby romaine. Romaine is the classic lettuce of choice for Caesar salads. Because it's said to have originated on the Aegean island of Cos, romaine is also called Cos lettuce. The term head lettuce describes those varieties on which the leaves grow in a dense rosette. Leaf lettuce describes the varieties with leaves that branch from a single stalk in a loose bunch rather than forming a tight head. The leaves are crisper and more full-flavored than those of the Head Lettuce varieties.