I finally found the image of flowers from the plant shown in my last post with berries. Here it is, as taken on May 15th, 2011.
It's a grab shot, and I think it isn't quite in focus, but you can plainly see that the flowers have 4 petals, so at this stage, you can tell (I should have seen) that it is not a viburnum, which would have had 5 petals. As you can see the leaves look better in May than they did by the time the plant had matured berries.
It is apporaching time to see the spring wild flowers on hills near SF again! In anticipation, here is a photo I took on May 2nd of 2011, on a trail above College of San Mateo. It shows a mix of plants. The ones I can identify are a blue Iris douglasii and a yellow version of paintbrush. That is prrobably coastal paintbrush, Castilleya latifolia, since the bracts (that look like flowers) of that species can be yellow as well as red. C. latifolia is native to coastal, central California.
The Iris you can grow in your garden, the paintbrush, not so much, since it has a semi parasitic relationship with adjacent plants that is hard to get underway on purpose.
These spring-like winter days make me ready for spring, though with an ominous feeling that we need some rain to make those spring flowers bloom!