The Mimosa Tree ( Albizia julibrissin ) is commonly called the silk tree or just mimosa. It is a nitrogen fixing legume, forming a symbiotic relationship with a bacterium in its roots. These bacteria form nodules on Mimosa roots and provide nitrogen (nitrogen fertilizer) to the tree. The Mimosa is native to the Middle East and Asia and was first grown in the United States in 1785. The Mimosa can grow 1’-3’ annually with regular water eventually reaching 20’-25’ tall and 25’-30’ wide. It generally grows with a spreading canopy that provides cooling shade over a wide area. The Mimosa Tree has fernlike leaves that are attached to stems alternately. Each leaf consists of groups of smaller leaflets. Mimosa leaves close slowly as darkness approaches and stay closed during the night. Mimosa flowers are produced in abundant clusters covering the tree through early summer. Its showy flowers attract hummingbirds as well as bees and butterflies. Individual flowe