In spring, Cytisus × praecox 'Allgold', also known as Scotch broom or Warminster broom, is covered with canary-yellow flowers topped with a pale yellow flag on a shrub maturing at 6 feet in height and width. Classified in the pea family, this species has flowers with a heavy fragrance that not everyone finds pleasant. Not reliably hardy in the Chicago area, this plant is also noted for its tolerance of salt spray and poor, acidic soils. The very small leaves are deciduous during droughts, leaving the task of photosynthesis to the green chlorophyll covering the densely twiggy stems and trunk.