Spanish Broom (Spartium junceum, syn. Genista juncea), also known as Weaver's Broom, is a perennial, leguminous shrub native to the Mediterranean region in southern Europe, southwest Asia and northwest Africa, where it is found in sunny sites, usually on dry, sandy soils. It is the sole species in the genus Spartium, but is closely related to the other brooms in the genera Cytisus and Genista.
Spanish Broom typically grows to 2-4 m tall, rarely 5 m, with main stems up to 5 cm thick, rarely 10 cm. It has thick, somewhat succulent grey-green rush-like shoots with very sparse small deciduous leaves 1-3 cm long and 2-4 mm broad; the leaves are of minimal importance to the plant, with much of the photosynthesis occurring in the green shoots (a water-conserving strategy in its dry climate). In late spring and summer it is covered in profuse fragrant pale yellow flowers 2 cm across. In late summer, its legumes (seed pods) mature black, 4-8 cm long, 6-8 mm broad and 2-3 mm thick; they burst open, often with an audible crack, spreading seed from the parent plant.
It has been widely introduced into other areas, and is regarded as a noxious invasive species in places with a Mediterranean climate such as California and Oregon, central Chile, southeastern Australia, and the Canary Islands.
In Bolivia, the plant is known as retama, and has become very well established in some areas. It is one of the most common ornamental plants, often seen growing along sidewalks in La Paz. Retama has made its way into the ethnobotany of the indigenous Aymara and Quechua cultures. Under the Spanish influence, those cultures have adopted the belief that retama can be used to ward off evil. Sprigs of flowering retama are often kept in the home, and street vendors will often lay a flowering branch of retama on top of their booths when they close up shop for the night.