The Marin County CNPS Facebook page reports
Some of the plants seen at Potrero Meadows were Viola adunca var. adunca (blue violet), Viola purpurea ssp. quercetorum (mountain violet), Castilleja densiflora ssp. densiflora (common owl’s clover), Gratiola ebracteata (vernal pool hedge-hyssop), and Githopsis specularioides (common bluecup).
Olompali State Park: Castilleja affinis, Delphinium variegatum, Fritilleria affinis, Lonicera hispidula, Mimulus aurantiacus.
See photos and older posts at https://www.facebook.com/groups/MarinNativePlants/
Natural History Wanderings 
I am seeing a few clumps of white poppies among the many orange, and both are the same family. Is this something new..
LikeLike
By: richards lyon MD on April 14, 2015
at 12:47 PM
I am guessing this is a genetic variation if the plants have identical structure and are the same species. In terms of frequency at your location you might check with the local chapter of the California Native Plants Society or if you are in another state check your state’s native plants society.
LikeLike
By: Sandy Steinman on April 14, 2015
at 1:13 PM