It is a low-growing perennial shrub growing to 20 t tall , or rarely to 1 m. It is found widely in Europe and Asia Minor on acidic soils in open sunny situations and in moderate shade . It is a low-growing perennial shrub growing to 20 t tall , or rarely to 1 m and taller , and is found widely in Europe and Asia Minor on acidic soils in open sunny situations and in moderate shade .