The generic name commemorates the Italian nobleman Filippo degli Albizzi, who introduced the plant into cultivation in the mid-18th century. The silk tree is believed to be native from Iran to Japan.
Silk trees are small trees with a short lifespan. Its leaves are small and fanlike. Silk tree flowers grow bright pink puffs in bundles. There are approximately 150 species, some of which are considered weeds.
The silk tree is sometimes grown as ornamental. It is also known as the pink acacia, Persian acacia and mimosa tree. One silk tree species, Albizia julibrissin, is now considered a highly invasive species to North America. It was introduced on shore in 1745. It now grows along roadsides, parking lots and near power lines.
The silk tree is used by the larvae of moths as food. It has a fragrant scent and is also known to attract bees, insects and hummingbirds.
The United States Department of Agriculture classifies the silk tree as a perennial shrub or tree that grows during the spring or summer months and is not fire resistant. The silk tree has fine foliage texture, flattened seed pods, is not toxic, and grows to a height of 20 to 25 feet tall. Silk trees have a rapid growth rate. Their bark is light brown, mostly smooth and generally thin with lens-shaped areas along the stem. Silk trees are rarely found about 3,000 feet elevation.
Once established in the environment, the silk tree is difficult to remove due to the long-lived, dangling seed pods and its ability to resprout vigorously. Silk tree seeds have seed coats that allow them to remain dormant for many years. One particular study showed that 90 percent of the seeds were still strong after five years.
The silk tree makes a beautiful lawn accent. Their leafy, graceful canopy permits enough light for grass to grow right up to the trunk. The silk tree is often planted around homes, decks and porches where they provide shade. They are susceptible to a fungus blight that attacks older, larger trees and kills them quickly. Fortunately, though, silk trees can grow as fast as 3 feet per year or more, so they can be quickly replaced if need be.
Silk tree wood has been used in furniture making. It enhances soil fertility by nitrogen fixation.
One researcher discovered a hybrid of Albizia julibrissin and another species, Albizia kalkora, growing near Duke University in North Carolina in 2006. The bark on the hybrid is smooth, and the hybrid appears to be a cross between the two species, exhibiting similar characteristics.