Clam chowder is any of several chowder soups containing clams and broth. In addition to clams, common ingredients include diced potatoes, onions, and celery. Other vegetables are not typically used, but small carrot strips and a garnish of parsley might occasionally be added primarily for color. A garnish of bay leaves also adds color, along with flavor. It is believed that clams were used in chowder because of the relative ease of harvesting them.