Desert plants that grow very long roots are called phreatophytes. These taproots allow plants to reach water that would otherwise be unavailable to them. Some plants have both tap roots and radial roots, which are roots that spread out shallowly, according to Desert USA. This maximizes the amount of scarce water that these plants can accumulate.
The mesquite has the deepest taproot of any desert plant. The mesquite plays a large role in the desert, replacing much of the nitrogen that is lost in the soil. These trees produce bean pods that are a major food source both for indigenous humans and for coyotes. The taproots of the mesquite are larger than the tree itself. Indigenous individuals often dig up the taproot as a fuel source.
The Honey Mesquite and the Screwbean Mesquites are smaller trees that reach about 20 feet tall, while the Velvet Mesquite reaches about 30 feet tall, according to Desert USA. The Honey Mesquite has creamy yellow flowers, the Screwbean Mesquite has light yellow flowers and the Velvet Mesquite has greenish-yellow flowers.
Four-Wing Salt Bush
Another plant that has a tap root system is the four-wing salt bush. These plants grow 2 to 3 feet tall, according to Desert USA. Scales known as scurf prevent these plants from losing water. The flowers grow in globule clusters. These plants are sometimes considered weeds and can be very difficult to eliminate, since their root systems can contain nutrients that will fuel regrowth.
White bursages are plants capable of surviving very dry conditions. Their outer cells dry and harden and they are able to found water at the water table with their very long tap roots. These plants mostly look lifeless until the spring comes, according to Bird and Hike. Then, they produce small leaves for photosynthesis and flowers that are barely noticeable, since they are small and green with a yellowish tint. They are about as tall as an average person’s knee, reaching up to 2 feet. Their fruit is light brown.
The creosote bush is the most commonly found bush in the desert. This bush often crowds out other plants for water, which is why they are so frequently seen. These bushes produce yellow flowers that have a twisted appearance, according to Desert USA. Their fruit is small, white and fuzzy. The leaves are very waxy and are adapted towards not losing water. These leaves have been used as antiseptics for native individuals.