Native to (or naturalized in) Oregon:
- Broadleaf deciduous shrub, 4-8 ft (1.2-2.4 m), dense, rounded mound, slender green branches. Leaves alternate, compound, 3-leaflets, each about 13 × 6 mm, obovate or lanceolate. Flowers sweet-pea shaped, bright yellow, about 2.5 cm long, solitary or in pairs, can cover the plant in spring and early summer, very noticeable. Fruit a pod, 4-5 cm long, hairy along the margin, green, finally brown.
- Sun. Drought resistant.
- Hardy to USDA Zone (5) 6 Native to central and southern Europe.
- Caution: This species is often considered an invasive shrub-weed, it establishes in abandoned areas and is very competitive since it is a nitrogen fixer. In February 2010, the Oregon Department of Agriculture amended its noxious weed quarantine (OAR 603-52-1200) to include Cytisus scoparius and the rule "prohibits the growing or sale of Scotch broom in Oregon regardless of the variety or cultivar. C. scoparius should not be grown or sold in Oregon."
- There are cultivars that are thought to be less aggressive than the species, but supporting data is minimal. Flowers colors range from white ('San Francisco'), pale yellow ('Moonlight'), lilac-pink ('Lilac Time'), orange and apricot ('Pomona'), to red ('Stanford').
- Oregon State Univ. campus: southwest Reser Stadium (probably a cultivar).