Extremely variable shrub: compact and rounded; sprawling and low; to open-branched and treelike. Flowers minute, greenish. Height: 6 ft (2 m); some to 15 ft (5 m).
Dry, often salty soils, sandy or gravelly flats, slopes in creosote bush, Joshua tree, sagebrush, blackbrush communities, piñon-juniper woods.
Western United States and southwestern Canada east to North Dakota and Texas.
This plant may accumulate levels of the soil mineral selenium, making it toxic to livestock.
