In an earlier post, I briefly mentioned the four North American deserts. Now I'll describe them in a bit more detail.
[Image]Sagebrush in the Great Basin Desert
Great Basin DesertThe Great Basin Desert is the biggest North American desert, covering most of the state of Nevada and extending into the states of Utah, Idaho, Oregon, and California. It is the only North American desert considered to be a cold desert, which is largely a function of its high elevation, with most basins above 4,000 feet in elevation, and mountaintops over 13,000 feet. Average annual precipitation is 6 to 12 inches. The term Great Basin originates from the fact that the water that falls in the Great Basin does not drain out to the ocean, but stays within the basin. It's really a bunch of basins separated by mountain ranges, but somehow trying to say that succinctly isn't easy.
The primary plant in the Great Basin Desert is sagebrush (Artemisia tridentata), a fragrant green-gray shrub that grows up to several feet high. Several species of sagebrush grow in the desert. Other common plants are winterfat, greasewood, rabbitbrush, and saltbush. Salt Lake City, Utah and Reno, Nevada are in the Great Basin Desert.
[Image]Lechuguilla in the Chihuahuan DesertChihuahuan DesertThe Chihuahuan Desert is the spiny desert, with lots of sharp plants. It is found primarily in Mexico, but a small portion creeps across the border and into New Mexico and Texas. It's the coolest of the hot deserts, with elevations ranging from 1,200 to 6,000 feet, and it receives up to 10 inches of precipitation annually.

While creosote bush and ocotillo are common, the distinctive plant in this desert is the lechuguilla (Agave lechuguilla). It's a member of the Agave family and has razor sharp spines. Other spiky plants are other agaves, yuccas, sotols, thorny mesquites, and a variety of cacti. El Paso, Texas and Carlsbad and Roswell, New Mexico are within the Chihuahuan Desert.
[Image]Saguaro cactus in the Sonoran DesertSonoran DesertThe Sonoran Desert is the neat cactus desert, with the characteristic saguaro cactus (Carnegiea gigantea) holding up its arms. In addition to this charismatic character, the Sonoran desert has the greatest species diversity of all North American deserts, despite being the hottest of the four deserts. 
Precipitation ranges from less than 2 inches to more than 12 inches. The desert creeps into southern Arizona and California, but the majority of it is found in Mexico. Phoenix and Tuscon, Arizona are part of the Sonoran Desert.
[Image]Joshua tree in the Mojave DesertMojave DesertThe Mojave is the smallest of the four North American deserts, but what it lacks in size it makes up in character. This is the desert with the Dr. Seuss-like Joshua trees (Yucca brevifolia).
The Mojave Desert is found between the Sonoran and Great Basin deserts in California, Nevada, Utah, and Arizona. It is a transition area between the two deserts, ranging in elevation from 2,000 to 4,000 feet on average, although it also includes Death Valley which descends below sea level and Mt. Charleston at over 11,000 feet. This is the driest of the four deserts, with 2 to 5 inches of annual precipitation. Las Vegas, Nevada and Palmdale, California, St. George, Utah, and Lake Havasu City, Arizona are in the Mojave Desert.
[Image]So in summary:Largest Desert: Great Basin (or Chihuhuan based on some maps)Smallest Desert: MojaveHottest Desert: SonoranDriest Desert: MojaveBest Desert: You decide
A great resource for learning more about these deserts and the plants that live in them is Ronald J. Taylor's Desert Wildflowers of North America. And now Desert Boy, Henry, and I are going to head outside to go enjoy another desert adventure.