Bridal broom, French broom, Portuguese broom, Scotch broom or Spanish broom
Retama monosperma, Genista monspessulana, Cytisus striatus, Cytisus scoparius or Spartium junceum
Brooms have invaded over one million acres in California. The flowers produce thousands of seeds that build up in the soil over time, creating dense thickets that obliterate entire plant and animal communities. Grows quickly, creating a fire hazard in residential landscapes. "Sterile" varieties haven't been independently verified or tested and are not recommended as substitutes.
“Sweet broom” (Cytisus spachiamus or Genista racemosa) is not known to be invasive. However, because we lack information on its potential for invading wildlands, we do not recommend it as a subsitute for other brooms.