Acacia trees and shrubs come from the Acacia genus, Fabaceae (legume) family, and Mimosoideae subfamily. With more than 1300 species and varieties worldwide, about 1000 of these are native to Australia. This plant is also found in Africa, Europe, Asia, and North and South America. Acacias are generally long-lived and fast-growing, often with deep roots that enable them to thrive under dry, drought conditions. Acacias have a variety of landscape uses. Most have clusters of flowers that are yellow or cream in color..
What appears to be leaves on some acacia trees are actually modified petioles, the parts of the stem that attach the leaves to the branch. When the petioles form in this manner, they are called phyllodes. The plant may start out with real leaves that change to phyllodes as it matures. Other species have a modified stem called a cladode. On the species that do have true leaves, the leaves are pinnately compound—consisting of rows of leaflets around a central stem.
Some species of Acacia include a psychoactive alkaloid in the leaves, seed pods, flowers, or stems. The psychoactive agent, known as DMT (dimethyltryptamine), is a powerful but short-lived hallucinogen that has been used for spiritual purposes by indigenous peoples.
Acacia acinacea, Acacia acuminata ssp. acuminata, Acacia burkittii, and Acacia adunca are all species known to contain this psychoactive substance, though none of these are common landscape plants.1 Accidental ingestion to a degree that produces psychoactive effects is very rare, but it has been suggested that you should use caution not to breathe the smoke when burning brush that that contains acacia plants. S
ome species also bear sharply modified stems or thorns which can be useful for preventing access in certain locations. If you choose a thorny variety be sure to place it away from high traffic areas.