Did you know? Organic lettuce is a fat free, low calorie food and is good for a well balanced diet. It is a valuable source of vitamin A and folic acid. Lactucarium is a mild opiate-like substance that is contained in all types of lettuce. Both the Romans and Egyptians took advantage of this property eating lettuce at the end of a meal to induce sleep.Organic lettuce is a temperate annual or biennial plant of the daisy family Asteraceae. It is most often grown as a leaf vegetable. In many countries, it is typically eaten cold, raw, in salads, sandwiches, hamburgers, tacos, and in many other dishes. In some places, including China, lettuce is typically eaten cooked and use of the stem is as important as use of the leaf!