Platystemon californicus
"Cream Cups"

Along with its close relative the California Poppy, this lovely native species is ideal for naturalizing in a wildflower or dry garden, though it grows perfectly fine in any well-drained garden soil. With its dainty spreading type habit (10" x 12") & grey-green foliage, it is smothered with delightful 1" flowers of creamy-yellow in Spring. It goes well with Larkspur, Cornflowers & Nemesia. 
Reseeds!