Chorizanthe valida is a rare species of flowering plant in the buckwheat family known by the common name Sonoma spineflower. It is endemic to West Marin, Marin County, California, where it is known from only one remaining natural population at Point Reyes National Seashore. It was thought to be extinct until 1980 when the Point Reyes population was discovered. Chorizanthe valida is a federally listed endangered species.