Arizona hosts 20 tree families, such as the Rubiaceae, Salicaceae, Sapindaceae, Sapotaceae and Ulmaceae. Native species of tree include the elm, sycamore, birch, pine and Douglas fir. Arizona also has 33 invasive species of tree, one of which is a palm.
Arizona's climate allows for a wide variety of plant species including desert and high altitude trees. Arizona hosts 4 million acres, 27 percent of total land in the state, of forested terrain.
The state tree of Arizona is the blue palo verde. It blooms with small, bright yellow flowers, has edible fruit, and can withstand extended temperatures of more than 100 degrees Fahrenheit without precipitation.