Our dogwoods have been flowering for three or four weeks. At first glance they look just like the Flowering Dogwoods of eastern North America, but then you notice that the white "petals," which are actually modified leaves or "bracts," are larger than those of Eastern Flowering Dogwoods. The East's Flowering Dogwoods bear four white bracts, but the ones here have four or more. You can see a fine close-up of a "flower" at www.californiagardens.com/Plant_Pages/cornus_nuttallii_closeup.htm.
Our California Dogwoods are CORNUS NUTTALLII. As is the case back East, we also have some dogwood species that produce small, not at all showy flowers.