1, kale and lettuce are two different plants. Kale is a vegetable, belongs to the cruciferous family, is an annual or biennial herb, its young leaves and young flower buds can be eaten. Lettuce is a vegetable that belongs to the lettuce family and is a perennial herb whose young stems and leaves are edible.

2, the edible part of kale is mainly young leaves and young flower buds, its young leaves are dark green, with a spicy flavor, often used in stir-fry or cold. The young flower buds of kale are yellowish-green, with a tender taste, and can be used in stir-fry or soup.

3, the edible part of lettuce is mainly young stems and young leaves, lettuce young stems are white or light green, the texture is crisp and tender, taste fresh, can be eaten raw or cooking. The young leaves of romaine lettuce are dark green and tender, and can be used for stir-frying or making soup. Overall, there is a clear difference between kale and romaine lettuce in terms of plant species, edible parts, and flavor.