For many, their vision of the Sonoran Desert, located in the southwest part of the United States and northern Mexico, is one of a vast and barren wasteland of rolling sand dunes and desolate landscapes. But nothing could be further from the truth, as the Sonoran Desert annually becomes a lush environment of amazing springtime color when the indigenous plants bloom after a winter of rain.
The Sonoran Desert is 120,000 square miles (311,000 square kilometers) in size and is situated in southern Arizona, southeastern California and the Mexican states of Sonora, Baja California and Baja California Sur. It is know for its extreme hot summer temperatures, its low relative humidity and a unique and diverse variety of plants and animals.
In early April, the Palo Verde trees first turn the Sonoran Desert landscape into a sea of yellow. There are two common Palo Verde species found in the Sonoran Desert the Blue Palo Verde (Cercidium floridum) and the Foothill Palo Verde (Cercidium microphyllum).
Palo Verde is a name given to these trees by the Spanish conquistadors when they first traveled this land in search of Cibola, the Seven Cities of Gold. The name translates to mean "green sticks." Bees become common visitors to this annual explosion of desert flowers. Honey made from the nectar of the Palo Verde flowers has been a long sought after treat by those who have made their homes in this harsh environment.
Mesquite trees are a very common sight in the landscape of the Sonoran Desert. Members of the Fabaceae family along with the Palo Verde, these desert plants replenish the nitrogen to the soil, benefiting all the plants that grow here. There are three common species of mesquite trees found here in the Sonoran Desert: Velvet Mesquite (Prosopis velutina), Screwbean Mesquite (Prosopis pubescens) and the Honey Mesquite (Prosopis glandulosa).
The flowers of the Honey Mesquite add to the desert springtime color. By late June these flowers will have developed into long bean pods that are a valuable source of food for the indigenous animals, and once the indigenous humans who made their homes in this beautiful desert.
Ironwood trees (Olneya tesota), shown here in bloom, are found only in the Sonoran Desert and can grow to a height of over 45 feet (14 meters) and live for more than 1,500 years in dry locations below 2,500 feet (760 m) in altitude. It too is a legume, a part of the Fabaceae family. The wood of this species is very hard and dense, even sinking when put into water.
The beautiful lavender-to-pink flowers of the Ironwood tree come in to bloom in late May/early June and provide edible seed pods in late July and August. The root of the Ironwood was once ground and used as a medicine by the native people. Temperatures may be 15 degrees cooler under the shade of a large Ironwood tree than in the open desert just 10 feet (3 m) away.
Brittlebush (Encelia farinose) is a member of the sunflower family and is the most common shrub of the Sonoran Desert. During long periods of drought, the yellow flowers and mint green leaves all wither and drop, leaving a bush of only brittle stems, thus giving rise to the plant's name.
During April the mountains of the Sonoran Desert turn yellow when the thousands of brittlebush growing there explode into bloom. The fragrant resin they produce has analgesic properties and was once used as a pain reliever. A boiled tincture made from the blossoms, leaves and stems of the brittlebush was known to be a powerful relief for anyone suffering a toothache.
Creosote bush (Larrea tridentata) is a common shrub found in the Sonoran Desert. The waxy, deep-green leaves with yellow springtime blossoms soon turn into white wooly seeds ready to be scattered by the wind. When the waxy resin on the leaves mixes with the water of a rain shower, a unique aroma is released that can be smelled for miles around, giving rise to the saying, "the desert smells like rain." Creosote bush was a powerful medicine plant for the native people and was used for stomach disorders, antiseptics and even to relieve the swollen limbs of the elderly. [Hold Your Nose: 7 Foul Flowers]
Fairy Dusters (Calliandra eriophylla) are common plants found along the washes of the Sonoran Desert. Their dainty springtime blossoms stand in great contrast to the rugged environment in which they grow. The pollinated flowers are soon followed by curled brown seed pods. This desert shrub loves the sun and heat and will grow to be 3 feet (1 m) in height.
Desert Milkweed (Asclepias subulata) is another of the common plants found along the washes and sandy flats of the Sonoran Desert. It too has been used for centuries as a source of many medicines by the indigenous people. This perennial plant can reach a height and width of 3 to 5 feet (1 to 1.5 m). The plant was once studied as a source of potential rubber by the U.S. Department of Agriculture but no commercial use of the rubber was ever begun.
The red, trumpet-shaped flowers of the Chuparosa bush (Justica californica) add a different color to the rocky slopes along the washes of the Sonoran Desert. It is a member of the tropical Acanthus family and is the only member of this group that has extended its range into the United States. The name "Chuparosa" was given to these colorful plants by the Spanish and it translates to mean "sucking rose." The flower is abundant in nectar and a favorite food source by the many species of hummingbirds that are found in the Sonoran Desert.
The Desert Globemallow, or Apricot Mallow, (Sphaeralcea ambigua) brings a sea of orange to the springtime landscape of the Sonoran Desert. With rain, the five-petal flowers can bloom year-round. This desert perennial herb grows in large clusters and can reach a height of 2 feet (0.6 m). It is also known as the Desert Mallow, the Desert Hollyhock and the Sore-eyed Poppy due to the tiny star-shaped leaf hairs that can irritate the eye if accidentally rubbed into it.
The Engelmann Hedgehog (Echinocereus engelmannii) is the first cactus of the Sonoran Desert to bloom each spring. It is one of the most common hedgehog cacti found in the desert, often found from the flat desert floor to the rocky lower slopes of the desert mountains. It is sometimes called the Strawberry Hedgehog due to the strawberry looking fruit that each of the beautiful fuchsia flowers produce.
For such beautiful white flowers, Sacred Datura (Datura wrightii) surely has some of the more colorful and unique of common names: "Jimsonweed" and "Devil's Weed." This common desert plant contains dangerous levels of poisons that can induce hallucinations. It is a dangerous plant to grazing animals and is a classical example of the contrast of beauty and danger found in the Sonoran Desert.
The indicator plant of the Sonoran Desert is the majestic saguaro cactus (Cereus giganteus). No springtime bloom has been more important to the indigenous animals and people than those of this tree-like cactus lovingly known as the "Sentinel of the Desert." These symbols of the desert can grow to be 50 to 60 feet (15 to 18 m) in height and live upwards of 200 years. And when their creamy white flowers begin to bloom in early May and fill the desert landscape, the sight is spectacular.
These 3-inch-long (8 centimeters), trumpet-shaped flowers with yellow centers are found in clusters at and around the end of the giant's columnar branches. The flower only remains open a short 24 hours and must attract its pollinators including bees, birds and long-nosed bats before tightly closing forever.
Since all the saguaro flower clusters do not bloom at the same time, the blooming cycle of a single saguaro cactus can last up to 6 weeks before all the blooms have opened and shut. If fertilization of the flower has occurred, the fruit begins to form immediately.
About three weeks after fertilization, the tip of the saguaro fruit, right under the base of the dried-up, once beautiful cream-colored flower begin to turn red. The mid-June through July annual desert feast is about to begin again. The Desert Sentinels will again feed the many creatures with whom they shares the Sonoran Desert.
The fruit turn redder and redder under the hot, June sun and all wait for the gift of food that is about to be unleashed. During the hottest and driest time of the year, the fruits of the saguaro cacti give the creatures of the desert life-sustaining nourishment until the earth-soaking rains come again upon the annual monsoon winds.
The fruit splits open exposing a bright-red pulpy flesh that drops to the ground, assuring the survival of the many animal species. The wine-smelling liquid found within the fruit can be processed into an intoxicating drink. Within that pulp is found upwards to 2,000 pin-head-sized seeds looking for the right condition to sprout and begin their slow growth toward becoming a part of the next generation of the Sonoran Desert's Sentinels.
This is only part of the story of springtime in the Sonoran Desert. It is a time of incredible floral beauty and magical lifecycles. By late July the deep green landscape filled with flowers of every color has dried up and turned back into many shades of brown. The desert will remain in its brownish hues until the winter rains come once again to set up another springtime explosion of colorful flowers from the amazing variety of indigenous plants that are found in the Sonoran Desert.