Plants

Desert Plants have it tough. They bake in the summer, freeze in the winter, and have to bear months without a drop of rain. It may not seem like much of a life for a plant, but surprisingly there is great diversity here. Since the desert is so young - geologically speaking - plants are still experimenting with different ways to survive.

Dead or Alive?

In the desert, there is often a thin line between dead and alive, and desert plants have a bag of tricks to stay on the living side of the line. Most have roots that reach wide or deep to get every drop of water they can. After rains, cactus swell like accordions, soaking up enough to see them through drier days.

Creosote Bush, Larrea tridentata
Creosote Bush, Larrea tridentata
The sharp smell of creosote bush comes from natural oils and wax which coat its leaves to seal in water. When times get drier, creosote leaves fold in half to cut their exposure to the sun. During the worst dry spells, the creosote bush will drop its leaves entirely, cashing it all in until the rains return.

Smoke Tree, Dalea spinosa
Smoke Tree, Dalea spinosa
It is often hard to tell whether a smoke tree is dead or alive. With a crown of gray branches and twigs with dense hairs, a smoke tree can look like smoke from a distance. Leaves appear on the tree for a few short weeks in the spring before the smoke tree blooms with purple flowers, usually in May and June.

Even the seeds of desert plants have protective coatings to keep them from sprouting until there is enough rain to grow.

Ocotillo, Fonquieria splendens
Ocotillo, Fonquieria splendens
An ocotillo can look lifeless most of the year. But within days of rain it will come alive and leaf-out with small leaves above its spines. If it dries out again, the ocotillo sheds its leaves. This cycle may repeat several times. The ocotillo blooms from March through June with red flowers at the ends of branches, even when there are no leaves on the plant.

Spikes and Spines

Desert Cactus bristle with needles, but what's the point of all those spines? They make sharp defense against clumsy hikers as well as hungry animals seeking cactus fruit or flesh. But for cactus, needles have other good points, too. Cactus lack leaves, so their needles help shade the plants from too much sun. And they help keep cactus cool by acting like the fins on a radiator into the air. In some cactus, downward pointing needles collect mist and dew which drips down to water their shallow roots.

Cat-claw Acacia, Acacia greggii
Cat-claw Acacia, Acacia greggii
Also known as "wait-a-minute" bush, cat-claw acacia is a common shrub found in the washes of the Colorado Desert. The branches are armed with short curved spines, much like a cat's claw.

Joshua Trees, Yucca brevifolia
Joshua Trees, Yucca brevifolia
Joshua trees belong to the Lily family. They were named by Mormons who, when they encountered this giant yucca tree, thought that it resembled the arms of Joshua beckoning them farther west. One of the most beautiful spectacles during spring in the Mojave is the creamy white blossoms of the Joshua tree. These white candles can be seen from February to late April.

Many members of the wildlife community depend on Joshua trees for food and shelter, but only the yucca moth has evolved a life-style very closely tied to the Joshua tree. The female moth has special organs with which to collect pollen from Joshua trees and other yuccas. She carefully spreads her hoard of pollen onto the receptive surface of the flower and lays her eggs in the flower's ovary. When the larvae hatch they feed on the flower's seeds. Without pollination, moth larvae would have no seeds to eat. They eat only a few, leaving plenty to shake free from the fruit and grow into the next generation of Joshua trees.

Riot of Color

For much of the year, the desert lies stark and dormant. But after rainfall, it comes alive with a parade of wildflowers. Some years the blooms are sparse. Other years, when temperatures and winter rains fall just right, brings a riot of color with fields of green, yellow, purple, and red, carpeting the desert floor.The best way to see wildflowers is to check below to find out what is currently blooming, and where current hot spots are. You can arrange a tour tailored to your time and the season. Listed below are several popular destinations during wildflower season:

• Antelope Valley California Poppy Preserve
• Anza-Borrego Desert State Park
• Death Valley National Park
• Joshua Tree National Park
• Mojave National Preserve
• Santa Rosa San Jacinto Mountains National Monument

Spring lasts from late February in the low deserts and can linger into May higher up. To catch the show, grab a good field guide and head on out. If you are not sure where to go, one of the wildflower hotlines can get you started.

In the Mojave Desert, look for gilias, desert primroses, phacelias, desert sunflower, lupines, desert marigold, prince's plume, and desert sunflowers.

In the Colorado Desert, common wildflowers include verbenas, evening primroses, gilias, and lupines.

Alien Invaders

Native plants are in constant competition with exotic species brought into the desert either accidentally or deliberately. The number of species effectively changing the vegetation landscape of the desert are too numerous to mention individually. Here are the more common introduced plants you may encounter.

Tamarisk, Tamarix ramosissima
Tamarisk, Tamarix ramosissima
Tamarisk, also know as Salt cedar, was brought to the desert because it grows quickly and provides a wind break and shade. A tamarisk tree can gulp 500 gallons of water a day. Native plants depending on that water will die. Tamarisk is difficult to remove and each plant can produce thousands of seeds. These seeds blow a long way before coming to rest and repeating the process.

Tumbleweeds, Salsola iberica
Tumbleweed, Salsola iberica
Also known as Russian thistle, tumbleweeds came to the desert from the steppes of Asia. This relatively recent arrival may have come in wheat shipped to South Dakota in the late 1800s. For many, the tumbleweed has become the emblematic plant of the west, immortalized in song and story. When mature, the plant rounds up, breaks loose at the root, and is whirled across the desert plains by strong winds, scattering its seeds as it "tumbles."

Halogeton, Halogeton glomeratus
Halogeton, Halogeton glomeratus
In the same family as the tumbleweed, halogeton too is from Asia. It has rapidly spread throughout millions of acres in the west and seems particularly well adapted to the alkaline soils and arid environment of the Mojave. This plant readily invades over-grazed land and produces toxins responsible for thousands of livestock poisonings.

Plants & People

Some people believe the desert is a lifeless place. In their view, the few scraggly plants that grow here are of little value to people. This overlooks the fact that native peoples survived in the desert for thousands of years through their intimate knowledge and seasonal use of many desert plant species.

Today, we are learning to appreciate desert plants for their stability to conserve water. Homeowners use native desert plants to landscape their homes and gardens. Instead of green, grassy lawns, yards now boast cactus, ocotillo, agave, palo verde, and other water-stingy plants.

Jojoba Plant, Simmondsia chinensis
Jojoba Plant, Simmondsia chinensis
One desert plant has played a major part in the recovery of an endangered species. For years, whales were hunted for their sperm oil which was used as an industrial lubricant and in the making of some perfumes. Once it was discovered that the seeds of the jojoba plant contain a high quality oil that can substitute for sperm oil, a number of desert farmers began to cultivate this native shrub for commercial uses. You may have even used shampoo containing jojoba oil. Use of jojoba, combined with strict conservation measures, has led to the significant recovery of sperm whale populations.

Many modern medicines contain plant extracts or synthetics. In fact, pharmaceutical companies hire researchers to comb nature for new medicines.