Romaine lettuce, also called cos lettuce, is distinguished by its tall head of robust dark green leaves with sturdy ribs down the center. Notably heat-tolerant, it stands out among other lettuce varieties. In North America, romaine is commonly sold as whole heads or as “hearts,” where outer leaves are removed and the remaining leaves are bundled together. With a history dating back at least 3000 years to 2700 BC, lettuce has been associated with the ancient Egyptian god of fertility, Min, due to its phallic shape. Romaine lettuce is particularly favored in the United States, accounting for about 30% of lettuce consumption in the country. It is frequently used in popular dishes such as Caesar salads, chop salads, and wedge salads