Erodium sp., possibly the common, Eurasian, and invasive weed, E. circulatum (red-stemmed filaree). I saw these all over. I did not set out to take a picture of one, but when I decided to include a sample flower picture in this gallery, I had no trouble finding an example among my other flower shots.
2016CA Coast RangeErodiumGeraniaceaePF
From Carrizo Plain - March 2016