I am told this is California coffeeberry (now Frangula californica ssp. californica), not hoary coffeeberry (F. c. ssp. tomentella). The latter is common in the serpentine soil on Trail 15. This is on the Birding Transect Trail, also near a serpentine outcropping. The flock of band-tailed pigeons was on this plant and the one beyond: coast live oak?? Or perhaps the pigeons were feeding on something on the ground, in the tarweed?? 9:25 am.