Deciduous erect shrub or small tree (4m x 2.5m) from Asia and Iran. Smooth heart shaped leaves on arching branches. Large heads in pairs of fragrant flowers in spring in shades of white, pink, mauve, lilac-blue and purple-reds. Useful as a small specimen tree or in the background of shrubbery for its spring flowers. Prefers a cool position and moist fertile alkaline soil. Sensitive to soil acidity.