• The cholla cactus is one of the desert's unique plants.cholla cactus 2 image by Paul Moore from Fotolia.com
  
  The desert is home to a wide array of uniquely developed plant life. Although plant types vary based on the type of desert and geographical location, most deserts have several plants in common, particularly cacti and succulents. The diverse plant life of the desert contributes to its beauty and also to the preservation of desert animal life.
  
  

Xerophyte Characteristics

• Most of the plants that are commonly associated with deserts are classified as xerophytes, including cacti and succulents. These plants have evolved to survive the intense climate of the desert, which usually involves unusual methods of water storage and conservation. Xerophytes can be recognized by a variety of characteristics, such as lack of leaves or hairy leaves, sunken pores on the plant's exterior (also called sunken stromata), and water storage tissues.
  
  

Phreatophyte Characteristics

• Phreatophytes are plants with complex root systems that allow them to draw water from deep in the earth. They are characterized by long roots; the mesquite tree has a root system of approximately 80 feet, making its roots the longest of any desert plant. Other phreatophytes, such as the creosote bush, have wide root systems, as well as specialized stromata that close during the day and open at night to lock in the maximum amount of moisture.
  
  

Perennial Characteristics

• Perennials are not specific to deserts; however, desert perennials have developed a few methods of survival in the intense heat and dry environment. Many desert perennials, such as the ocotillo plant, have a dormant period during intense dry periods. Some desert perennials, such as the Ajo lily, can go into a dormant period for years before blooming.
  
  

Annual Characteristics

• Desert annuals are also referred to as "ephemerals." Unlike annuals of other climates, desert annuals do not necessarily bloom once a year. The plants can remain dormant for several months or even years, and tend to bloom rapidly after rainfall. Desert annuals will often only bloom for a few days, or even a few hours. Examples of desert annuals include the desert sand verbena and the desert yellow fleabane.