Baccharis pilularis, called coyote brush (or bush), chaparral broom, and bush baccharis, is a shrub in the daisy family native to California, Oregon, Washington, and Baja California. The plants are found in a variety of habitats, from coastal bluffs, oak woodlands, and grasslands, including on hillsides and in canyons, below 2,000 feet (610 m).
Coyote brush is known as a secondary pioneer plant in communities such as coastal sage scrub and chaparral. It does not regenerate under a closed shrub canopy because seedling growth is poor in the shade. Coast live oak, California bay, Rhus integrifolia, and other shade producing species replace coastal sage scrub and other coyote bush-dominated areas, particularly when there hasn't been a wildfire or heavy grazing.
In California grasslands, it comes in late and invades and increases in the absence of fire or grazing. Coyote bush invasion of grasslands is important because it helps the establishment of other coastal sage species.