Romneya coulteri - Matilija Poppy, Fried Egg Poppy

Deciduous perennial to 6 ft. Pale grey-green leaves emerge in spring. Sports the largest flower of any CA native plant, with crinkly white petals and a yellow center. Absolute show-stopper during spring and summer bloom. Cut back in fall to maintain tidier garden appearance. Spreads voraciously in sandy soils, difficult to establish in clay soils. Full to part sun. Low water. Hardy to 10º F.