Scotch broom

Cytisus scoparius

Other common names: broomtops, common broom, European broom, Irish broom, Scottish broom
 
Why is it a noxious weed?
It displaces native and beneficial plants, causing loss of grassland and open forest. It aggressively spreads to form monocultures, replacing desirable forage grasses and young trees. Seeds are toxic to livestock and horses.
 

How would I identify it?

General Description: Scotch broom is a perennial, many-branched, shrub ranging in height from 3 to 10 feet tall.

Flower Description: Flowers are typical of those in the pea family. They are bright yellow, about 3/4 inches long and have 5 petals.

Leaf Description: There are few leaves. The upper are simple and the lower are 3 parted. They are deciduous and pointed at both ends. Leaves may fall early in the year, leaving bare green stems.

Stem Description: Stems are woody and dark green. Young branches have 5 green ridges with hairs. When mature, stems become glabrous and ridges disappear. Young stems remain green throughout the year.

Fruit/Seed Description: Seed pods are brown-black, legume-like, flattened and have hairy margins with several seeds per pod.

May be confused with: Spanish broom (Spartium junceum) and French broom (Genista monspessulana), Class A noxious weeds in Washington, and gorse (Ulex europaeus), a Class B noxious weed in Washington, look similar to Scotch broom. Spanish broom has round stems and flowers only at stem tips. French brooms's leaves are all three-parted and flowers are in clusters of 4-10. Gorse has spines on its stems. If you need help with plant identification, please contact your county noxious weed coordinator.

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