Beneath each spine you ll see a small patch of green, where enough chlorophyll is stored to permit the plant to carry on photosynthesis between rains, when the plant is leafless. Other physical adaptations allow desert plants to thrive where their more moderate climate cousins would perish. Whitish hairs cover the leaves of ceniza and mariola, shrubs of Big Bend s middle elevations. The white color reflects the sun s burning rays, while the hairs hold the moisture and minimize the drying effects of wind on the surface, creating a more moderate microclimate on the leaf s surface. Creosote bush and tarbush produce a sticky resin on their leaves, a sort of waterproofing agent that reduces the amount of moisture lost to evaporation.
Some plants cope with desert conditions by growing only where the environment is milder.
Mexican buckeye, Mexican persimmon and desert willow grow best in drainages where water concentrates. Mosses and even ferns can be found growing in protected crevices and shady nooks where water accumulates after rain. More than 1000 species of plants are found in Big Bend, making it one of the richest desert parks, biologically speaking. Several factors account for the surprising wealth of plant and animal life found in the Chihuahuan Desert. Big Bend encompasses huge variation in elevations, from 7,800 foot Emory Peak in the Chisos Mountains, to the Rio Grande near the eastern boundary of the park, flowing about 1,800 feet above sea level.