Helianthus x. multiflorus? Here is a link that might be useful: Helianthus x multiflorus

thanks for the help, it did seem to be taking over the area, at least its rather attractive...

Clearly a Commelina, but it doesn't look like the Commelina communis that I've seen, those having longer, narrower leaves that are pointed at the tip, as well as generally being much larger plants than your pictures seem to indicate. A search on the USDA PLANTS Database also shows that Commelina communis isn't reported to occur in California. Only one species is reported in California, Commelina benghalensis, which is listed as a noxious weed by the state of California. So presumably that's what you have. I've linked a web page (from Hawaii) with information about that species, which has pictures showing that the leaf shape matches yours closely. Patrick Alexander Here is a link that might be useful: hear.org: Commelina benghalensis

Cochlospermum vitifolium?