In general, there are five types of lettuce:
- Butterhead varieties, sometimes called cabbage lettuce, form a small, loose, slightly flattened head that looks like an open rose. Buttercrunch, Boston, Bibb, Limestone, and Four Seasons are the best-known butterhead lettuce varieties.
- Crisphead lettuce has a solid spherical head of tightly-wrapped, pale green leaves that are crisp and succulent. Crispheads have a neutral, watery flavor, and it is most commonly known as head lettuce or iceberg lettuce. Varieties of Crisphead include Great Lakes, Ithaca, and Imperial. Batavian lettuce is a French type of Crisphead that opens like Looseleaf lettuce but later develops a dense head at maturity.
- Looseleaf lettuces form tight rosettes of individual leaves that are crisp and buttery-flavored. Looseleaf do not form hearts or heads. Looseleafs can be yellow, green, red, reddish-bronze, or purplish in color. Its varieties are often named for their appearance, such as the Green Ice, Red Sails, Black-Seeded Simpson, Lollo Rosa, and Salad Bowl.
- Romaine lettuce has a large, upright, loaf-shaped head with long narrow stiff leaves that look coarse but are crisp, tender, and sweet. The inner leaves are greenish-yellow surrounding a succulent heart. The ancient Romans gave Romaine lettuce its name, which is Caesar salad's chief ingredient. Common Romaine lettuce varieties are Rouge D'Hiver, Jericho, and Paris White Cos.
- Celtuce, or stem lettuce, is grown for its succulent, thick stem and tender leaves. The name celtuce is a combination of celery and lettuce. The flavor of celtuce is similar to celery, cucumber, zucchini, and artichoke, or a combination of the four. The stem of celtuce can be pared to remove its bitter skin leaving the soft translucent green core that can be finely sliced and eaten raw in a salad.