romaine lettuce

Romaine lettuce (Lactuca sativa var. longifolia), also known as cos lettuce, is a cultivar of common lettuce originating in the Mediterranean region, particularly around the Greek island of Cos. The plant develops an elongated, upright head with sturdy, mid-ribbed leaves that are darker green on the outer layers and pale yellow-green toward the center. The leaves have a crisp, firm texture and a mild, slightly sweet flavor with subtle nutty undertones. Unlike softer lettuce varieties, romaine maintains structural integrity when dressed, making it mechanically distinct among salad greens. The heart—the tender inner leaves—is especially prized for its delicate flavor and pale coloration.

Romaine lettuce is the traditional base of Caesar salad, where its sturdy leaves withstand heavy dressings without wilting. It is extensively used in Mediterranean and North American cuisines for composed salads, sandwiches, and wraps. The crisp leaves are suitable for both raw applications and light cooking; some preparations involve braising or grilling to develop deeper flavors. Romaine pairs well with anchovy-based dressings, citrus vinaigrettes, and cheese. The inner heart leaves are often served whole or minimally cut to showcase their tender texture, while outer leaves are typically chopped or shredded for mixed green preparations.