scoparius (Common Broom; syn. Sarothamnus scoparius) 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,
where it is found in sunny sites, usually on dry, sandy soils at low altitudes.
It typically grows to 1-3 m tall, rarely 4 m, with main stems up to 5 cm thick, rarely 10 cm. It has green shoots with small deciduous trifoliate leaves 5-15 mm long, and in spring and summer is covered in profuse golden yellow flowers 20-30 mm from top to bottom and 15-20 mm wide. Flowering occurs after 50-80 growing degree days. In late summer, its legumes (seed pods) mature black, 2-3 cm long, 8 mm broad and 2-3 mm thick; they burst open, often with an audible crack, spreading seed from the parent plant. It is the hardiest species of broom, tolerating temperatures down to about -25°C.