Ambrosia deltoidea (Triangleleaf Bursgage)

This Sonoran native is the main understory plant for much of the desert around Phoenix and Tucson. It functions as a nurse plant to the seedlings of many other natives and is essential for most revegation efforts. This evergreen rounded shrub has small, aromatic, triangular gray-green leaves. The insignificant flowers are followed by small burs covered with hooked spines. It is capable of surviving without supplemental irrigation, but looks more lush with summer waterings. In irrigated landscapes this plant tends to be short-lived, although it will reseed. A relative of ragweed, it may cause allergic reactions for some people.