DESCRIPTION: Shrub up to 10'. Leaves compound, with two leaflets joined at the base. Leaves are evergreen, dark green to yellowish-green, often shiny with wax and less than 0.5" long. Flowers are yellow and have 5 petals. Flowers may occur any time, but peak in spring and again in winter. Fruit is a white, fuzzy, ball about 0.25" in size. Zygophyllaceae (Caltrop) Family.
NATURAL HISTORY: Try this -- hold (you don't have to break off) some twigs with leaves in your hand, blow into your hand (increasing the humidity just like when it is or is about to rain), then sniff inside your hands. You're going to breath in "the smell of rain"! To all desert rats, that fragrance is uplifting! The aroma comes from chemicals in the foliage that are emitted right before and during rains. And this magnificent odor will follow you everywhere you go in the desert southwest because the Creosote Bush is one of the most common shrubs in the Sonoran, Chihuahuan, and Mojave Deserts (but not the Great Basin Desert -- it's too cold). Speaking of cold, right at the end of the last ice age about 11,000 years ago, a creosote bush individual began growing, and it is still growing today!! This would make it the oldest individual on Earth. Creosote Bushes grow in ever-widening circles, with their center bushes dying out and sprouting new bushes to the outside (thus no one twig is 11,000 years old).

Of all perennial plants in North America, the Creosote Bush is thought to be the most drought-tolerant. It can go without rain for at least two years, and survive in areas receiving only 3" of rain per year on average. The Creosote Bush is important for both people and other creatures. To the O'odham, who live in the Sonoran Desert, this was the first plant created and is the most widely used plant for medicinal purposes. One man in his 70s that I knew in Idaho drank tea made from the creosote bush ("chaparral tea") every day and claimed he had never been sick since the day he started drinking the tea (on the other hand there have been deaths blamed on drinking the tea [ASDM 2000]). As far as animals go, many insects feed on the plant, both its nectar and pollen (22 bee species and counting) and, in some cases, its leaves. The Creosote Bush Grasshopper is one of those, and another interesting species is the Creosote Bush Gall Midge (Asphondylia). This small fly lays eggs on twigs, the larvae hatch, and chew into the twigs. Chewing by the larvae, cause the bush to grow a ball of deformed leaves (a gall). The larvae live inside these galls, feeding on the plant material and protected from predators and the elements until they emerge as flies.