Colutea is a genus of about 25 species of deciduous flowering shrubs from 2-5 m tall, native to southern Europe, north Africa and southwest Asia. The leaves are pinnate and light green to glaucous grey-green. The flowers are yellow to orange pea shaped and produced in racemes throughout the summer. These are followed by the attractive inflated seed pods which change from pale green to red or copper in colour.
Colutea arborescens, known as Bladder Senna, is indigenous to the Mediterranean; it has yellow flowers. It has a height and spread of up to 5 m. Other species include Colutea orientalis, with grey leaves and coppery flowers.
Colutea arborescens will grow in poor sandy soils as well as heavy or loamy soils and is easy to propagate from seed. It is generally pest resistant, though garden snails will climb up the plant in wet weather to eat the leaves. It has become naturalised in the UK. The hybrid Colutea x media (C. arborescens x C. orientalis) is also cultivated for its coppery flowers.