Distribution: Distributed widely throughout much of Washington, especially in lowlands west of the Cascades crest; Alaska to California, east to Idaho and Montana; also in eastern North America.
Habitat: Widespread noxious weed, usually where somewhat moist.
Flowers: April-June
Origin: Introduced from Europe
Growth Duration: Perennial
Conservation Status: Not of concern
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.
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.
PNW Herbaria: Specimen records of Cytisus scoparius in the Consortium of Pacific Northwest Herbaria database
WA Flora Checklist: Cytisus scoparius checklist entry
OregonFlora: Cytisus scoparius information
E-Flora BC: Cytisus scoparius atlas page
CalPhotos: Cytisus scoparius photos