Cytisus scoparius

Scotch broom


The Basics

Taxonomy: Kingdom - Plantae (plants). Subkingdom - Viridiplantae (Green plants). Superdivision - Embryophyta. Division - Tracheophyta (Vascular plants). Class - Magnoliopsida. Order - Fabales. Family - Fabaceae (Peas, legumes). Genus -Cytisus Desf. Species - Cytisus scoparius (L.) Link

Habitat: Scotch broom, also called Scot's or English broom, is commonly found in areas somewhat moist.

Invasive Spread: Scotch broom is native to northern Africa and parts of Europe, ranging from northern Africa north to Sweden and the British Isles and east to Ukraine. Scotch broom has been introduced to many parts of the world as an ornamental. In North America, Scotch broom was introduced to Virginia in the early 1800s for use as fodder for domestic sheep. It was considered invasive in this area by 1860. Scotch broom was introduced to California as an ornamental in the 1850s, was widely used for roadside erosion control in the early 1900s, and was recognized as a problem in California in the 1930s.

The current North American distribution of Scotch broom is along the Atlantic coast from Nova Scotia to Massachusetts, Delaware, Virginia, and Georgia; along the Pacific coast from British Columbia to central California; and inland to Idaho, Montana, and Utah. It also has scattered occurrences in several inland states in the eastern United States, and occurs in Hawaii. The worst infestations of Scotch broom occur from British Columbia to central California, from the coast to the inland valleys: primarily west of the Cascade Range in Washington, Oregon and west of the Sierra Nevada in California. In California, Scot's broom occurs on more than 700,000 acres in central to northwest coastal and Sierra Nevada foothill regions. Occurrences are also reported further south in the interior valleys of Los Angeles, San Bernardino, Riverside, and Orange counties, and Scot's broom is beginning to invade chaparral and lower montane habitats in the San Bernardino Mountains.

Scotch broom and striated broom are 2 of 4 nonnative invasive broom species that occur in North America. Spanish broom (Spartium junceum) and French broom (Genista monspessulana) occur in similar habitats and have some similar morphological and ecological characteristics. Common gorse is another leguminous shrub that occurs in similar habitats, but is morphologically distinct from the brooms.


General: Deciduous shrub up to 3 m. tall, the branches strongly angled, pubescent to glabrous. Leaves alternate, trifoliate at the base of the branches, becoming simple above, the leaflets obovate and entire.

Flower & Fruit: Flowers usually solitary in the leaf axils, on long pedicels, yellow or purplish-tinged, pea-like, 2-3 cm. long; calyx cup-shaped, bilabiate, the upper lip 2-lobed, the lower 3-lobed; stamens 10, 4 longer that the other 6; style strongly curved, longer than the keel. Pods flattened, glabrous except for the villous margins.


Cytisus scoparius reproduces and spreads from abundant seeds and can also sprout from stumps or root crowns following damage or destruction of aboveground biomas.

Fire Ecology

Cytisus scoparius sprouts from the stem after top-kill from fire or mechanical removal. Its ability to sprout seems to vary with season and severity of damage, although this relationship is unclear and deserves further investigation. A single intense fire can reduce Scotch broom cover, but is likely to encourage germination of Scotch broom from the seed bank and at least temporarily reduce cover of native perennials such as Idaho fescue. A second fire is necessary to kill broom seedlings within 2 to 3 years, before Scotch broom seedlings are reproductively mature. It is unclear how the presence of brooms may affect fire regimes in invaded communities. In general, in ecosystems where broom replaces plants similar to itself (in terms of fuel characteristics), brooms may alter fire intensity or slightly modify an existing fire regime. However, if broom invasion introduces novel fuel properties to the invaded ecosystem, they have the potential to alter fire behavior and potentially alter the fire regime.

Species Distribution


USFS Plant Database
Habeck, R. J. 1992. In: Fire Effects Information System, [Online]. U.S. Department of Agriculture, Forest Service, Rocky Mountain Research Station, Fire Sciences Laboratory.

USDA Plants Database
USDA, NRCS. 2017. The PLANTS Database. National Plant Data Team, Greensboro, NC 27401-4901 USA.

Integrated Taxonomic Information System
Cytisus scoparius

Burke Museum of Natural History and Culture
Burke Museum. 2016. Cytisus scoparius [Online]. University of Washington.