If you live in an older part of the Tucson area, you might have the Ginkgo tree (Ginkgo biloba) in your landscaping. Although related to the conifer, it does not have needles. The leaves are small, fan shaped and leathery in texture. A deciduous tree, the leaves turn golden-yellow in the fall.
The history is a bit interesting. At one time it was found world-wide, but now is native only to 2 areas in China. A very tough tree, it is often planted in cities with high air pollution, as it doesn’t seem to mind.
Ginkgo makes an interesting specimen tree for the Tucson desert, but certainly not in a native landscape. Ginkgo does not have insect or disease problems, and can tolerate our alkaline soils. It needs regular water to reach tree size, and once mature you can cut back the watering somewhat with no ill effects. The tree grows anywhere from 40 to 50 feet tall, depending on the variety.
Reference: Sunset Western Garden Book, Sunset Publishing Corp. 2001