In much of the Chihuahuan desert, shrubs, succulents, and cacti, dominate the landscape, while trees are few in number and in total number of species. Trees generally need more water, cooler temperatures, and higher humidity than the desert climate has to offer, and that restricts them to ridge tops, canyons and riparian zones. Those that do grow in the lower desert elevations, such as honey mesquite, Prosopis glandulosa, often grow no taller than shrubs and are easily confused with shrubs because they possess similar physical characteristics such as small leaves and sharp spines.
Shrubs, on the other hand, are numerous and widespread in the Chihuahuan desert. Average elevations in this desert (above 3000’) allow for colder winters which many shrub species can tolerate, while most cacti and succulents cannot.