Sagebrushes are mostly highly branched aromatic woody shrubs with evergreen leaves, but they can be herbs as well. California sagebrush is the only sagebrush that grows in chaparral that has woody stems and long linear thread-like leaves often with several leaflets which branch off of them (generally less than 2 cm (.78 in)) with its margins curled under. The common desert sagebrush (big sagebrush, A. tridentata) by contrast has thick wedge-shaped 3-lobed leaves and generally occurs at high elevations or in interior semi-desert habitats.

Well-established California sagebrush stands are important habitat for the California Gnatcatcher, which is a federally threatened bird. Oils produced or stored in the stems and leaves of California Sagebrush contain several toxic terpenes, which make them unpalatable to livestock  and to most wild plant-eating mammals. These oils may also account for both its aromatic scent and the fact that the soil beneath these shrubs is usually bare of other seedlings. In fact, the moisture that condenses on and then drips from the surfaces of Sagebrush leaves following the first autumn rains are toxic. Many insects forage on its leaves, making these shrubs a rich source of nutrition for insect-eating birds and small mammals.