Sassafras is a native North American tree known for its distinctive leaves, aromatic bark, and deep roots in American culinary and folk medicine traditions. The species most people mean when they say “sassafras” is Sassafras albidum, a medium-sized deciduous tree that grows 30 to 60 feet tall and ranges from Maine to Florida and west to Texas. It’s the tree that originally gave root beer its flavor, and it remains a staple of Creole cooking in the form of filé powder.
How to Identify a Sassafras Tree
Sassafras is one of the easiest trees in North America to identify, thanks to an unusual trait: a single tree produces three completely different leaf shapes. You’ll find simple oval leaves, two-lobed “mitten” shapes (complete with a thumb), and three-lobed leaves that look like a trident or fork. All three types can appear on the same branch. The leaves are bright green, typically 4 to 6 inches long and 2 to 4 inches wide, and they turn vivid shades of orange, red, and yellow in autumn.
Beyond the leaves, every part of the tree is aromatic. Scratch the bark or crush a leaf and you’ll notice a spicy, root-beer-like scent. The bark is reddish-brown and deeply furrowed on mature trees. Small yellow-green flowers appear in early spring before the leaves emerge, and female trees produce dark blue berries on bright red stalks in late summer.
Where Sassafras Grows
Sassafras is native to eastern North America. Its range stretches from southwestern Maine west through southern Ontario and central Michigan, then southwest through Illinois, Missouri, eastern Oklahoma, and eastern Texas, and back east to central Florida. It’s a common sight along roadsides, in old fields, and at forest edges. The tree is shade-intolerant, meaning it thrives in open sunlight and struggles under a dense canopy. It prefers slightly acidic to neutral soils with a pH of 6.0 to 7.0, and on good sites with little competition, young sprouts can grow up to 12 feet in just three years.
Culinary Uses: Filé Powder and Root Beer
Sassafras has two famous roles in American food. The first is filé powder, made by drying and grinding sassafras leaves into a fine, green-gray seasoning. Filé is an essential ingredient in traditional Louisiana gumbo, where it serves as both a thickener and a flavoring agent. The powder adds an earthy, slightly sweet taste and gives the dish its characteristic silky texture when stirred in at the end of cooking. This use traces back to the Choctaw people of the Gulf Coast.
The second is root beer. Oil extracted from sassafras root bark was the original flavoring in root beer and several other soft drinks. That changed in 1960, when the FDA banned the addition of safrole (the dominant chemical compound in sassafras root bark oil) to food products. Today, commercial root beer uses either artificial flavoring or a safrole-free sassafras extract. That extract is made by processing the bark with dilute alcohol, concentrating it through vacuum distillation, then diluting with water and discarding the oily fraction that contains safrole.
Why Safrole Was Banned
Safrole makes up roughly 80 to 90 percent of the essential oil distilled from sassafras root bark. Animal studies found that dietary exposure to safrole caused liver cancer in both mice and rats, including when administered during infancy. Based on this evidence, the National Toxicology Program classifies safrole as “reasonably anticipated to be a human carcinogen.” The FDA prohibits its direct addition to any food intended for human consumption.
It’s worth noting that filé powder, made from the leaves rather than the root bark, contains only trace amounts of safrole and is not subject to the ban. The leaves have a very different chemical profile than the root bark. The estimated average daily intake of safrole from all dietary sources in the general population is about 0.3 milligrams, a figure that reflects background exposure from spices and natural foods rather than deliberate sassafras consumption.
Traditional and Folk Medicine
Long before European settlers arrived, Native American tribes used sassafras for a wide range of ailments, primarily infections and digestive problems. The root bark was brewed into teas, and poultices were made from the leaves and bark. European colonists adopted many of these practices, and sassafras root tea became one of the first exports shipped from the American colonies back to England, where it was marketed as a cure-all.
By the 20th century, sassafras tea was a common spring tonic in rural Appalachia and the American South, believed to “thin the blood” after winter. None of these traditional uses have been validated by modern clinical research, and drinking tea brewed from sassafras root bark does expose you to safrole.
Wildlife and Ecological Value
Sassafras plays an important role in its ecosystem. The leaves are a primary food source for several moth and butterfly species, most notably the spicebush swallowtail, a striking black and blue butterfly found throughout the eastern United States. Female spicebush swallowtails can detect sassafras by “tasting” leaves with sensors on their front legs. Once they identify a suitable tree, they lay their eggs on the leaves. The caterpillars, sometimes called leaf rollers, spin silk onto a leaf surface that contracts as it dries, folding the leaf into a daytime shelter. At night, the larvae emerge to feed.
The dark blue fruits are eaten by songbirds, wild turkeys, and black bears, making sassafras a valuable food source in late summer and early fall. Because the tree readily sprouts from its root system, it often forms dense thickets that provide cover for small mammals and ground-nesting birds.
Growing Sassafras
Sassafras is a moderately fast-growing tree that does well in home landscapes across its native range. It needs full sun and well-drained soil. A slightly acidic to neutral pH (6.0 to 7.0) is ideal. The tree tolerates a range of soil types, from sandy to loamy, but doesn’t do well in heavy, waterlogged clay.
One thing to know before planting: sassafras spreads aggressively through root suckers. A single tree can send up shoots several feet from the trunk, eventually forming a colony if left unchecked. This makes it excellent for naturalizing a large area or stabilizing a slope, but it can be a nuisance in a tidy yard. The tree also has a deep taproot, which makes it difficult to transplant once established. If you’re planting one, start with a young tree and put it in its permanent spot from the beginning.