SAGE-BRUSH, any one of the species of the genus Artemisia — composites very abundant in the arid, alkaline regions of the western United States, where the soil is not too saline, and, with other desert vegetation, covering immense areas. The best-known sage-brush is the common shrub, or bitter-sage (A. tridentata), which is found growing on the plains and ascending to the sub-alpine parts of the mountains. It varies in different situations from a dwarfed shrub to almost tree-like proportions, when its trunk near the ground will measure nearly a foot through, being twisted and knotty and loosely enveloped in a light-gray, shreddy bark.