|California Bush Sunflower (Encelia californica) blooming in the Heritage Creek Nature Preserve on the Cal State Dominguez Hills campus|
The yellow sunflower that's in full bloom right now is California Bush Sunflower, Encelia californica. This local native shrub is one of our early spring bloomers; it can flower all the way through spring in some years. California Encelia is very drought tolerant - the plants at Heritage Creek Preserve (above) are never watered. They become dormant in summer, then re-leaf each year with the rains.
To learn more about California Encelia see: http://mother-natures-backyard.blogspot.com/2013/03/plant-of-month-march-california-bush.html
For a gardening sheet on this plant see: http://www.nbs.csudh.edu/biology/projectsound/native_plants/gallery_e.shtml