Spanish broom is a perennial, evergreen shrub that can reach six to ten feet tall. The erect, bright green stems are rounded (rush-like) and mainly leafless. The stems branch off at the top, ending with flowering clusters on leafless racemes. The leaves are simple and one-parted, (as compared to the three-parted leaves of Scotch broom); they are alternate, short-lived, and less than one inch long. The leaf shape is linear to lanceolate. Hairs are present on the lower surface. The leaves are the same bright green color as the stems. The flowers are fragrant, bright yellow, and pea-shaped, approximately one inch long. The flowers grow in clusters at the branch ends, on stalks that can be 18 inches long. The flowers bloom from July to frost. The fruits are hairy seed pods, flat and linear, up to three inches long. Spanish broom spreads by seed. Spartium junceum is the only species of this genus. Distinguishing characteristics include the round stems, the simple one-parted leaves, and the fragrant flowers.
Native of the Mediterranean region and Canary Islands. Spanish broom was introduced as an ornamental for sale in a San Francisco nursery in 1858 - it has since naturalized in California. Distribution of Spanish broom is not well known, partially because of the resemblance to Scotch broom. In Oregon, all Spanish broom infestations are subject to control.