Scotch broom

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Code: t55
Latin name: Cytisus scoparius
Source material: Pollen
Family: Fabaceae (Leguminosae)
Common names: Scotch broom, Common broom, English broom, Broom tops, Irish tops, Basam, Bisom, Bizzom, Browme, Brum, Breeam, Green broom

Synonym: Sarothamnus scoparius

Allergen Exposure

Geographical distribution
Scotch broom is a perennial, leguminous shrub native to western and central Europe, from the Iberian Peninsula north to the British Isles and southern Scandinavia, and east to Poland and Romania (1). It has been introduced into several other continents outside its native range and is classified as a noxious invasive species in many countries, including the US (on the East Coast and in the Pacific Northwest), South Africa, Australia and New Zealand. It typically grows to 1-3 m tall, with main stems up to 5 cm thick. It has green shoots with small deciduous trifoliate leaves 5-15 mm long. Its long, slender, erect and tough branches grow in large, close fascicles, making it apt for broom-making.

In spring and summer, it is covered in profuse golden-yellow flowers 20-30 mm long and 15-20 mm wide. In late summer, its seed pods mature, becoming black, 2-3 cm long, 8 mm broad and 2-3 mm thick; they burst open, often with an audible crack, spreading seed.

There are 2 subspecies. Scotch broom is widely cultivated as an ornamental plant.

The twigs and branches are used for making brooms and also for basket-work. Parts of the plant have been employed medicinally, and are thought to be diuretic and cathartic.

No allergens have been characterised.

Potential cross-reactivity


Clinical Experience

IgE-mediated reactions
Anecdotal evidence suggests that asthma and hayfever are possible following exposure to pollen from this plant; however, no studies have been reported to date.

Other reactions
Attempts have been made to develop biological controls in affected areas, using Broom-feeding insects, e.g., the psyllid Arytainilla spartiophylla, the beetle Bruchidius villosus, and the moth Leucoptera spartifoliella (1). Since allergic reactions have been reported to these insects, they should be considered as potential allergens in individuals thought to be allergic to pollen from this plant, but in whom specific investigations are negative.

Compiled by Dr Harris Steinman,


  1. Wikipedia contributors, ”Cytisus scoparius”, Wikipedia, The Free Encyclopedia, (accessed July 3, 2008)


As in all diagnostic testing, the diagnosis is made by the physican based on both test results and the patient history.