Delphinium luteum A. Heller

Delphinium luteum A. Heller. Delphinium luteum, known by the common name yellow larkspur, is a species of small perennial herb in the buttercup family bearing bright yellow cornucopia-shaped flowers. Endemic to the rocky, foggy hillsides of coastal Sonoma County, California, it is critically endangered, with about 200 individuals believed to be in existence as of 2005.