The Blossoms In The American Southwest
Text & Photography by Roxane Hopper
When mountains block the path of precipitation, they cause rain shadows: vast areas of dry land. This describes the deserts of the American Southwest. The little precipitation that does fall (typically less than ten inches a year) evaporates quickly under the blaze of the ever-present sun, often before it meets the ground. In such cruel conditions, it’s a wonder anything exists at all, let alone blooms. But desert floras have adapted well with cunning mechanisms: they have developed deep and extensive taproots. And far-reaching, upward-extending secondary roots capture moisture from light rainfall. Some floras emit sap to make transpiration nearly impossible. Certain desert shrubs shed their leaves during dry spells, and then leaf out again after a rain.
Then there are the cacti and their fantastic adaptations. Cacti have transferred photosynthesis from leaves to their complex, plump stem, and they have carefully cultivated leaflessness. Hardy and fierce, they store water in their stems and sport areoles––the furry spots from which spines and flowers emerge. Their spines, which are in fact highly modified leaves, have numerous functions and forms. In addition to protecting the cactus from thirsty birds and rodents, spines provide shade and reduce airflow over the surface of the plant so as to help prevent water loss. While not all cacti have spines and some spiny shrubs appear to be cacti, one surefire cactus indicator is flower anatomy. Almost all cacti have an inferior ovary located beneath the other flower parts and boast dozens of stamens, the pollen-producing organ of the flower. An ocotillo with its spiny branches may look like a cactus, but the flower proves otherwise. It is such a bizarre sight in the landscape, to see the ocotillo’s tall, craggy branches topped with red flowers.
Driving through the desert, seeing the strange plants feels extraordinary, like one is discovering the land for the first time. In the spring, the scene of the enveloping sky and the horizontal stretch is graced with the blurring colors of poppies, primrose and coreopsis. We can observe these annuals blooming in localized areas in the spring, but to see the infamous explosions of color, provisions are strict. Seeds must germinate in the fall, and regular triggering rains, at least an inch per month, are essential throughout the spring. Additionally, spring temperatures must create the right conditions. With our changing climate, this is becoming trickier to anticipate. The ideal circumstances can be as infrequent as every 10 to 20 years. But when ephemerals bloom in great quantity, it is a feast for eyes. It is also a feast for migrating pollinators.
While some plants are pollinated by wind, others must attract animals to help them procreate. These plants flaunt flowers that offer nectar to winged migrators, fueling their various journeys. The Sonoran, Mojave and Chihuahuan deserts are on the migration path of many winged pollinators, including hummingbirds, doves, bats and butterflies. Unfortunately, these migratory corridors are being threatened by plant invasion, land conversion, pesticides and herbicides. Desert perennials (smaller herbaceous plants, cacti, shrubs and trees) have less fastidious blooming requirements, making them a more reliable food source. The tube-like, bright-red ocotillo and penstemon blooms attract the rufous hummingbird. Their flower structure is a prime example of mutualism––how plant and animal have evolved together. Flowers of the iconic Saguaro cacti open at night when they are visited by the lesser long-nosed bat, and they remain open during the day for honeybees and white-winged doves. One of the most fascinating mutualistic relationships of the desert is the yucca, exclusively pollinated by yucca moths. That these plants have adapted and developed these mutualistic relationships speaks to their survival and strength. Their glorious blooms––little markers of desert beauty––do their part in the grand scheme of nature to preserve their kind, and we must do our part to conserve the land and these species.
To observe desert blooms this season or for frequent wildflower updates, visit desertusa.com.