Spanish broom is a perennial, evergreen shrub that can reach six to ten feet tall. The erect, bright green stems are rounded and mainly leafless. The stems branch off at the top, ending with flowering clusters on leafless racemes. 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 bright yellow and pea-shaped. 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. Spanish broom is the most drought resistant of the broom species. It establishes in areas with full sun and limited water and it can grow in poor, rocky soils.