Rob,
You might have success using the Calflora web site. I am not familiar with Polygala californica, however using Calflora I found the Polygala californica listing and a photograph that matched perfectly. As stated earlier, there are convenient links to the Jepson Manual online with keys. Even keys to the families. The folks at Calflora have put much effort into creating an easy-to-use format and I think that they have succeeded.
As a side note, Marin County is a Phytophthora ramorum hot spot!
It is a disaster what has happened there. I would use great caution if and when visiting the area. Actually Phytophthera ramorum is spreading rampantly up and down the coast of California from the San Francisco Bay Area. Fortunately, Phytophthera ramorum does not seem to do well in the hot, dry, inland areas of California, so its spread inland is somewhat limited,.... at least right now.
