Isocoma menziesii is a species of flowering plant in the daisy family, known by the common names San Diego goldenbush and Menzies' goldenbush. It is native to California, Baja California, and Baja California Sur, where it grows in coastal and inland habitat such as chaparral, particularly in sandy soils.
I. menziesii is a subshrub forming a matted bush reaching between one and two meters (40-80 inches) tall. The erect branching stems may be hairless to woolly, are generally glandular, and vary in color from gray-green to reddish brown.
The leaves are oval-shaped to somewhat rectangular, gray-green and sometimes hairy and glandular, and 1–5 centimeters (0.39–1.97 in) long with stumpy teeth along the edges.
The abundant inflorescences are clusters of thick flower heads. Each head is a capsule with layers of thick, pointed, greenish phyllaries. The head is filled with large, protruding, cylindrical yellow disc florets with long stigmas.