Baccharis pilularis is variable in form, depending on its habitat, which ranges from coastal bluffs to wooded hillsides and canyons; plants can be up to 15 feet tall and rounded, like a small tree, or low and mat-like. Lower stems become woody, while the upper stems, the leaves and the phyllaries are all hairless, though somewhat glandular. All plants are freely branching, and produce many leaves at closely-spaced intervals, from the ground to just beneath the inflorescence. Leaves have a center vein and two main side veins, forking off near the base. Leaves may be attached via a very short stalk, or directly to the stem.

Flowerheads have a bell-shaped involucre enclosed by several rows of light green phyllaries, not recurved. The heads are composed of disc florets only, no rays, and these are of two types, either pistillate or staminate, numbering in the range 19 to 43 and 20 to 34 respectively. A single plant has only one type of flowerhead.

Ssp consanguinea is a tall plant with large leaves, while ssp pilularis is a mat-forming variant with smaller leaves, found in coastal areas; beach margins and exposed bluffs.