Ambrosia salsola, commonly called cheesebush, winged ragweed, burrobush, white burrobrush, and desert pearl, is a foul-smelling, scraggly perennial shrub common in deserts of the southwestern United States and northwestern Mexico. This species easily hybridizes with the white bur-sage (Ambrosia dumosa).
It is common on sandy desert flats, desert dry washes, and is weedy in disturbed sites in creosote bush scrub, shadscale scrub, Joshua tree woodland, and Pinyon juniper woodland, ranging from Inyo County, California, to northwestern Mexico.
It grows in sandy and gravelly soil, and sometimes on lava formations at elevations of 200–1,800 m (660–5,910 ft).
It is native to the southwestern United States (Arizona, California, Nevada, Utah) and northwestern Mexico (Sonora, Baja California, Baja California Sur), where it is a common plant of the local deserts, where it thrives on sandy soil, alkaline environments, and disturbed sites.
Leaves are narrow and needlelike (linear), thread-like (filiform), sometimes up to 65 mm (2.6 in) long but a mere 1.5 mm (0.059 in) across.
The foliage and stem tips have a foul, pungent, cheese-like scent when crushed, a trait which gives the plant the common name "cheesebush".
It flowers from March to June. Numerous small, cuplike male flowers grow in spike-like clusters above the female heads growing in the leaf axils. All female (Pistillate) flower heads contain only one flower, while all male (staminate) heads may contain 5-15 flowers.