Romneya coulteri (2lt)

Papery, pure-white, poppy-like flowers with golden-yellow centres from July to October and deeply lobed, grey-green leaves. This suckering herbaceous perennial is excellent in drifts on its own or to the back of a sunny mixed border. Often slow to establish and resentful of disturbance, it requires fertile, well-drained soil, and shelter from strong winds. Height and spread to 2m.