Plants play a critical role in the ecosystems of White Sands National Monument, stabilizing the leading edges of the dunes and providing both food and shelter for wildlife. Humans too have made extensive use of the dunefield's native plant life, using some for food and others to create things like cloth and medicine. However, it isn't easy eking out a living here in this harsh landscape.
In order to live in the nutrient-poor alkaline soil of the dunefield, the flora here must be tough—only the hardiest plant species of the Chihuahuan Desert grow here. They are drought tolerant and able to survive in temperatures that range from sub-freezing to over 100ºF (38ºC), depending on the season. Many of these plants can tolerate the high soil concentrations of salt present in the monument, while others (known as gypsophiles) absolutely thrive in these conditions.
Because the dunefield is in constant motion, the soaptree yucca, hoary rosemary mint, skunkbush sumac, and Rio Grande cottonwood have each found techniques to survive the waves of sand that eventually overwhelm other species. The soaptree yucca, for example, pushes itself ever higher on a lengthening stem. Both hoary rosemary mint and skunkbush sumac send tangled roots throughout the dune, holding onto the sand and building a cement-like pedestal around itself. The plants themselves grow taller, enabling them to survive even after the dune has moved on.
Another pedestal-builder, the Rio Grande cottonwood, simply allows the sand to pile up around its trunk. It then extends its branches higher and higher as the dune grows around it. As long as it keeps its leaves above the sand, it's able to get enough light for photosynthesis.
Between the dunes in the interdunal areas of the monument, grasses and smaller plants thrive. For plants like alkali sacaton, little bluestem, Indian ricegrass, and Mormon tea, survival depends on rapid growth, pollination, and reseeding at the far side of the interdunal space. Although an individual plant might perish, its offspring continue t succeed and colonize these areas.
Other native plants of the Chihuahuan Desert are found in the surrounding desert scrub environment, such as four-winged saltbush, pickleweed, and rubber rabbitbrush. Plant-lovers will also find tree cholla, claret-cup cacti, and soaptree yucca interspersed throughout this area.
The Desert in Bloom
Each season presents a different floral show, bringing splays of color to the white dunes. The stars of spring and early summer are the stately cream-colored blooms of the soaptree yucca. Reaching high above the dunes, the yucca flower stalks herald in a new year of beauty. Purple sand verbena, yellow blazing star, white pepperweed, and pale green-yellow Hartweg's sundrops burst forth in April. In May, yellow evening primrose, greenthread, and bright pink gypsum. centaury add to the show. Cacti add a touch of bright red on tree or cane cholla and the mounding claret cup.
Some of spring's blooms brave the summer's heat. Pepperweed, blazing star, and gypsum centaury linger on into the early summer months. Late summer brings tall spikes of orange blooms on the beautiful globemallow.
Autumn displays a show of color all its own as mounds of rubber rabbitbrush turn golden yellow and the leaves of the skunkbush sumac change into a brilliant rusty red. Rio Grande cottonwoods wave yellow-orange leaves and cowpen daisies nod yellow heads in gentle fall breezes.