Depending upon the area of the park that you visit the common trees and shrubs will vary. Down along the Rio Grande you will find riparian vegetation, in the desert the shrubs may be well spaced but there is a high diversity nonetheless. Once you reach the higher elevations of the Chisos mountains you will find a piñon-oak-juniper forest.
Riparian trees and shrubs
The most obvious trees and shrubs in the campgrounds along the river are cottonwood, mesquite, and huisache. As you leave the more manicured areas, typical vegetation by the river also includes willows, retama, and the invasive pest tamarisk or saltcedar.
Shrubs are the most dominant type of vegetation in the desert. The most common shrubs in the desert are creasote bush, ocotillo, cenizo, sotol, and mesquite. Also at desert springs you might find willows or cottonwoods along with other more riparian vegetation. The desert ecosystem heavily relies upon the presence of shrub vegetation as do many of the other plants and animals.
Mountain trees and shrubs
Though the most common trees in the Chisos mountains are piñon, oak, and juniper. There are a great number of other types of trees, many occur at this elevation and cannot be found for tens to hundreds of miles. Of those, the quaking aspen, douglas fir, drooping juniper, and ponderosa pine standout as the most popular.