broom：A shrub, Sarothamnus (or Cytisus) Scoparius (family Leguminosæ), bearing large handsome yellow papilionaceous flowers; abundant on sandy banks, pastures, and heaths in Britain, and diffused over Western Europe. Also the genus to which this belongs, and the allied genus Genista, including the White Broom, and Giant or Irish Broom cultivated in gardens, and many other species.——牛津当代大辞典  @en