A powder of dried, ground sassafras leaves used as a seasoning and as a thickening agent in soups and stews, particularly the famous filé gumbo. Oils in the bark of sassafras root contain safroles, a carcinogen, and sassafras tea and other products have been banned by the U.S. Food and Drug Administration. However, the powdered leaves do not contain safroles, and filé is considered safe for consumption.