Even in the Mexican border, desert oak, juniper and manzanita cover the mountains, and there is a vigorous though short-lived growth of grasses and flower from July to October.
The chamiso and the manzanita, with a variety of shrubby oaks and thorny plants, often grow together in a dense and sometimes quite impenetrable undergrowth, forming what is known as " chaparral "; if the chamiso occurs alone the thicket is a " chamisal."