Long stems bearing balls of pale blue flowers grow on a hot, rocky hillside. Narrow, fernlike leaves grow up each stalk. This is bluehead gilia (Gilia capitata), a hardy native to California and most other western states.
Bluehead gilia is good for sunny native plant gardens, where it self-sows and attracts bees, butterflies, and other pollinators. A member of the phlox (Polemoniaceae) family, it is also known as blue field gilia, globe gilia, and blue thimble flower.