Sagebrush n. : A low irregular shrub (Artemisia tridentata), of the order Compositae, covering vast tracts of the dry alkaline regions of the American plains; -- called also sagebush, and wild sage.

Example:
How do I care for a Southern Sagebrush Lizard?

Taxonomy
sagebrush, Artemisia tridentata, big sagebrush, California Sagebrush, Flora, subsp, plant, unranked, free encyclopedia, the leaves, A. Gray, Syn, Rydb, Beetle, species, cattle, liver, family Asteraceae.

Defination from the web:
sagebrush can grow as tall as 3 m (10 feet), but is more typically 1-2 m tall. ... Cattle that resort to sagebrush due to the lack of other fodder in the winter often freeze to death before starving, as they rely in large part ...