Semi-arid deserts have slightly more rainfall than dry deserts. According to the University of California Museum Of Paleontology, semi-arid deserts have approximately 1 to 1.5 inches of rainfall a year, while dry deserts receive less than about a half inch of rainfall. In the United States, semi-arid deserts are found in the sagebrush areas of Utah and Montana as well as portions of the Great Basin Desert.
The jujube (Ziziphus jujube) is a thorny tree that grows to 40 feet tall. Originally from China, the jujube thrives in the hot conditions of semi-arid deserts in the southwestern United States. The ornamental jujube grows spiny branches in a zigzag pattern. This deciduous tree goes dormant in the winter and can survive sub-freezing temperatures. The jujube develops slightly fragrant flowers from late spring until summer. Jujube fruit is highly edible and can be used for cooking, jellies and syrups.
The brittlebush (Encelia farinose) is a member of the sunflower family that grows in semi-arid deserts, as well as throughout the hot Sonoran and Mojave deserts. This small shrub grows into a 5-foot tall mound with brittle branches and hairy leaves. The deciduous brittlebush blooms from March to June with bright yellow flowers, providing color throughout its semi-arid desert regions. In the past, Native Americans used the resin from the brittlebush as glue. The Seri Indians of Mexico spread ground brittlebush over their bodies as a pain reliever.
The triangle-leaf bursage (Ambrosia deltoidea) is found in semi-arid deserts as well as the Sonoran desert. This small shrub grows to a rounded mound 1.5 feet tall, with its brittle branches developing into a crown with a mixture of healthy, old and dead growth. The leaves are shaped like a triangle and are gray-green on the topside and white on the bottom. The leaves and branches are hairy when young, becoming smoother as they mature.
The triangle-leaf bursage develops small flowers from February through July, followed by the development of seeds with a burr-like surface. These seeds readily stick to animal fur, allowing the seeds to be transported throughout the desert. This plant has a distinct root zone, as other plants will not grow near the triangle-leaf bursage's root system.