San Diego County, California, US
Very common shrub along the paths here - this one was almost in bloom - tiny little star-shaped white flowers (second photo).
Rhamnus californica (syn. Frangula californica), commonly known as coffeeberry and California buckthorn, is a species of flowering plant in the family Rhamnaceae, the buckthorns. It is native to the southwestern United States and Baja California in Mexico. It is an introduced species in Hawaii.