Albizia, sometimes spelled Albizzia, is the name of a species of legume-producing trees. Typically, Albizia are flowering trees, averaging 10-30 feet tall. Varieties of Albizia can be found in the Americas, Asia, Africa, and Australia. An herb made from Albizia bark has been used for centuries in India to treat a wide variety of ailments.
Albizia trees are tropical and subtropical members of the pea family of plants that produce legumes. A legume is a pod which typically splits down the middle and has seeds inside. Some legumes are edible; examples include peanuts, peas, soy, and lentils. The legumes produced by most Albizia trees are, however, not edible.
Most Albizia tree varieties have fine, lacy leaves, often resembling the leaves of a fern. In addition to seed pods, Albizia trees produce flowers that are typically pink, with a yellowish tint toward the center. The blooms are rounded with a delicate, airy quality and grow in bunches. Albizia are deciduous, meaning they lose their leaves during the winter season. The trees grow rapidly, but have a short life span, usually lasting only 10-20 years, can abide by a wide variety of soil types, and are drought tolerant.
Albizia trees have many other names, including silk trees or sirises. Probably the most commonly recognized variety of Albizia is called the Mimosa. Originally from Asia, and found in some southern U.S. locations, the Mimosa is considered an "invasive species." This term refers to any plant or animal that is non native to an area with the potential to cause ecological harm to the surroundings. Because they grow rapidly and reseed easily, Mimosa can crowd out native plants.
Most Albizia trees display some form of thigmonasty, an automatic response to stimuli in some plants. When touched, or when sensing strong vibrations in the area, the leaves of an Albizia tree curl back, lay flat, or fold in on themselves. This drastically reduces the size of the branches and protects the delicate leaves from potential damage.
One variety of the tree, Albizia lebbeck, also known as the Lebbeck Tree or Woman’s Tongue Tree, is native to Asia. The bark of the tree stems is used to create an herb called Pit Sirish which is generally available in pill and liquid form. Pit Sirish is reported to be beneficial in reducing high cholesterol. Because the herb contains histamines, it apparently can also provide relief to asthma and allergy sufferers. Pit Sirish is also said to relieve eczema and other skin conditions.