The short, linear leaves of thymophylla acerosa
are not lobed, but clustered, at opposite intervals all along the stems. Plants are shrubs, the leaves and stems bright green in color, usually covered with very fine, short hairs (puberulent). Leaves have distinct yellowish oil glands at intervals, from the base to just below the pointed tip. Stems branch from the base and higher up. Plants bloom all year, reflecting the mild desert environments they inhabit, but most strongly in summer.
At the base of the flowerhead are 5 leaf-like bractlets, about half as long as the phyllaries, which number about 13, and are fused apart from near the tips, with indistinct margins. Bractlets and phyllaries also have oil glands. Heads are formed of 7 or 8 yellow ray florets and 18 to 25 or more yellow-orange disc florets; fewer than most similar species