These are abronias, commonly called sand verbenas. The two species we have on this coast are either purple or yellow. However, in the past decade people have been reporting white sand verbenas. I have seen these color morphs before but this patch near Waddell Creek was the largest patch of the morph I have ever seen. Some botanist friends of mine say there is still debate over what the white verbenas are, whether they are a hybrid of the other varieties or a color morph of the yellow sand verbena species.