Also called Hamburg parsley and turnip-rooted parsley, this parsley subspecies is grown for its beige, carrotlike root, which tastes like a carrot-celery cross with a touch of celery root. It's used in soups, stews and simply as a vegetable. Parsley root is in season from about August to May. Choose firm roots without soft spots; the leaves should be feathery and bright green. Refrigerate in a plastic bag for up to a week. Remove leaves just before using roots, which may be peeled or not. The leaves may be used in the same manner as regular parsley.