Tree Poppy, with crepe papery petals and egg yolk centre.
romeyna
Commonly called matilija (ma-tila-huh) poppy, this California native wildflower is perfect for the dry, rocky, sun-baked west- or south-facing territory that is so difficult to make presentable.
Earth laughs in flowers 
this is one of my favorite flowers at Descanso Gardens. They are done blooming here. Nice work!
Thanks Pat, they flower here into September.