Salad leaves are a type of leafy green vegetable that are commonly used in salads. The two most popular salad leaves are greens and LETTUCE. Greens, which is six letters long, refers to any edible leafy green vegetable such as spinach, kale, and arugula. LETTUCE, which is seven letters long, is a type of leafy green vegetable that is usually used in salads. Both greens and LETTUCE are popular ingredients in salads and other dishes.