Low, dense growth of shrubby vegetation or stunted and dwarf trees in arid and semi-arid regions of the southwestern U.S. The coast range foothills of California are characterized by Atriplex canescens (four-wing saltbush), Ceanothus spp., and Arctostaphylos spp. (manzanita). In other places, dense thickets of Prosopis spp. (mesquite) and thickets of oaks may be called chaparral.