Gorse is an exotic invader from Europe, originally introduced as an ornamental. It is a spiny evergreen shrub in the pea family, dense and stiff, forming impenetrable thickets. Vigorous stands grow outward, crowding out all other vegetation and forming a center of dry dead vegetation. This, in combination with the oil content of the plant, presents a major fire hazard. In 1936 the town of Bandon, Oregon, was burned to the ground; 14 people died and only 16 buildings remained unburned. The disaster was fueled by extensive infestations of gorse.
Legal status in King County, Washington
Gorse is a Class B noxious weed. Property owners in King County are required to control this plant. This species is also on the Washington quarantine list (known as the prohibited plants list) (external link) and it is prohibited to transport, buy, sell, offer for sale, or to distribute plants or plant parts, seeds in packets, blends or "wildflower mixes" of this species, into or within the state of Washington.
Biology and morphology
Its erect angular stems have spreading branches ending in thorns. Green leaves take the form of branching spines. Flowers are yellow and shaped like pea-blossoms, clustered near the ends of the branches. They are solitary or with two to three grouped in axils of spines on the preceding year's growth. Fruit pods (legumes) resemble pea pods that burst expelling seeds. Roots are very extensive, with woody crowns and nitrogen fixing nodules. Gorse resembles Scotch broom (Scot's Broom).
Additional information on gorse
What to do if you find this plant in King County, Washington
Please notify us if you see gorse growing in King County. Our program staff can provide the property owner or appropriate public agency with site-specific advice on how best to remove it. We map all known locations of regulated noxious weeds such as gorse in order to help us and others locate new infestations in time to control them.
Gorse photos - click thumbnail for larger image