Sassafras trees grow from 9.1–18 m (30–59 ft) tall and spreading 7.6–12 m (25–39 ft). The trunk grows 70–150 cm (28–59 in) in diameter, with many slender branches, and smooth, orange-brown bark. The branching is sympodial. The bark of the mature trunk is thick, red-brown, and deeply furrowed. The wood is light, hard, and sometimes brittle. All parts of the plants are very fragrant. The species are unusual in having three distinct leaf patterns on the same plant, unlobed oval, bilobed (mitten-shaped), and trilobed (three-pronged); rarely the leaves can be five-lobed. They have smooth margins and grow 7–20 cm long by 5–10 cm broad. The young leaves and twigs are quite mucilaginous, and produce a citrus-like scent when crushed. The tiny, yellow flowers are five-petaled, and bloom in the spring; they are dioecious, with male and female flowers on separate trees. The fruit are blue-black, egg-shaped, 1 cm long, produced on long, red-stalked cups, and mature in late summer. The largest sassafras tree in the United States is located in Owensboro, Kentucky, which measures over 100 feet high and 21 feet in circumference.
The Lauraceae or laurel family, are aromatic, evergreen trees or shrubs. Many botanical species have similar foliage to the Lauraceae due to convergent evolution. Those plants are adapted to high rainfall and humidity. But the Sassafras genus and one or two other genera in Lauraceae are deciduous. It is a phenomenon of divergent evolution from the large evergreen trees, to occupy another ecological niche. The patterns of speciation in the Lauraceae family indicate that since the onset of aridification on the continents 15 million years ago, rainforest species diversified. One of the products of aridification is the isolation of populations, and this likely caused the increase in the rate of speciation as found in the Lauraceae.
The Sassafras genus responded to favourable climatic periods and expanded across the available habitat, adapting also to more extreme conditions, but depending on favorable soil edaphic conditions, as presence of aquifers, groundwater periodic flows, etc. This genus occur as opportunistic species across a wide distribution with close relatives and few species.
Deciduous sassafras trees lose all of their leaves for part of the year, depending on variations in rainfall. In deciduous tropical Lauraceae, leaf loss coincides with the dry season in tropical, subtropical and arid regions. In temperate or polar climates, the dry season is due to the inability of the plant to absorb water available to it only in the form of ice.
In convergent evolution, ecological or physical coincidences drive toward a similar solution, including analogous structures. Sassafras is commonly found in open woods, along fences, or in fields. It grows well in moist, well-drained, or sandy loam soils and tolerates a variety of soil types, attaining a maximun in southern and wetter areas of distribution. It is a phenomenon of divergent evolution from the large evergreen trees, to occupy another ecological niche. Its pattern of speciation is the product of aridification of its habitat. Sassafras expanded in favourable climatic periods across the available habitat and adapted to more extreme conditions, cooler and drier, but depending yet on favorable soil edaphic conditions, as presence of aquifers, groundwater periodic flows, etc.
In Sassafras, the dispersal of seeds is due to birds that swallow them, so the berries shape is attractive to birds. The fruits are an important food source for birds.
·Sassafras tzumu (Hemsl.) Hemsl. - Chinese sassafras or Tzumu, central and southwestern China, it differs from S. albidum in the leaves being more frequently three-lobed, the lobes having a tapered acuminate apex (not rounded to weakly acute).
·Sassafras randaiense (Hayata) Rehd. - Taiwanese sassafras, Taiwan, is treated by some botanists in a distinct genus as Yushunia randaiensis (Hayata) Kamikoti, though this is not supported by recent genetic evidence, which shows Sassafras to be monophyletic.
Steam distillation of dried root bark produces an essential oil consisting mostly of safrole that once was extensively used as a fragrance in perfumes and soaps, food and for aromatherapy. The yield of this oil from American sassafras is quite low, and great effort is needed to produce useful amounts of the root bark. Sassafras extract was a primary ingredient in root beer. Commercial "sassafras oil" generally is a byproduct of camphor production in Asia or comes from related trees in Brazil. Safrole is a precursor for the clandestine manufacture of the drug MDMA (ecstasy), as well as the drug MDA (3-4 methylenedioxyamphetamine) and as such, its transport is monitored internationally.
The dried and ground leaves are used to make filé powder, an ingredient used in some types of gumbo.
The roots of sassafras can be steeped to make tea, and were used in the flavoring of traditional root beer until being banned for mass production by the FDA. Laboratory animals that were given oral doses of sassafras tea or sassafras oil that contained large doses of safrole developed permanent liver damage or various types of cancer. In humans, liver damage can take years to develop and it may not have obvious signs. Along with commercially available sarsaparilla, sassafras remains an ingredient in use among hobby or microbrew enthusiasts.
In 1960, the FDA banned the use of sassafras oil and safrole in commercially mass-produced foods and drugs based on the animal studies and human case reports. Several years later, sassafras tea was banned, a ban that lasted until the passage of the Dietary Supplement Health and Education Act in 1994. Sassafras root extracts which do not contain safrole or in which the safrole has been removed are permissible, and are still widely used commercially in teas and root beers.
During the establishment of the Virginia Colony, including Jamestown in the 17th century, sassafras was a major export commodity to England. A medicinal root and a wood prized for its beauty and durability, sassafras was popular from its first import by Sir Walter Raleigh in 1602 until the 18th century. During a brief period in the early 17th century, sassafras was the second-largest export from America behind tobacco. Additionally, throughout history, sassafras wood has been found to be an excellent fire-starter because of the flammability of its natural oils found within the wood and the leaves.
2.^ abcNie, Z.-L., Wen, J. & Sun, H. (2007). "Phylogeny and biogeography of Sassafras (Lauraceae) disjunct between eastern Asia and eastern North America". Plant Systematics and Evolution267: 191–203. doi:10.1007/s00606-007-0550-1.
3.^ abWolfe, Jack A. & Wehr, Wesley C. 1987. The sassafras is an ornamental tree. "Middle Eocene Dicotyledonous Plants from Republic, Northeastern Washington". United States Geological Survey Bulletin1597:13
4.^ Dirr, Manual of woody landscape plants. Page 938.