Joshua Tree's Otherwordly Roots
Two Deserts, One Park
Two very distinct deserts meet in Joshua Tree. At elevations below 3000 feet, and temperatures up to 120 degrees, the Colorado Desert –– the hottest subsection of the much larger Sonoran Desert –– covers the eastern part of the park. The higher and cooler western side is in the Mojave. As you approach the park from this side, examples of its namesake dot the hills that border both sides of Park Blvd.
Cell signals will be spotty or non-existent once you reach the park entrance up the hill, so stop at the Visitors Center to download a map of the park for offline viewing. You can do this in the parking lot but it’s a good idea to go inside to pick up an old-fashioned paper copy, just in case. Oh, and water if you don’t have any. There’s nowhere in the park to buy any. Same goes for gas. Make sure you have a full tank.
While you’re at the Visitors Center, you can see a plastic replica of a Joshua tree in case you didn’t notice any of the 8 million+ real ones outside!
Dr. Seussian or Drunk?
Dubbed “charismatic” and “Dr. Suessian” in many a Mojave travelogue, this crooked monocot looks a little drunk, like it’s staggering through the desert scrub on the verge of tripping.
Officially known as the Yucca brevifolia, the Joshua tree is a member of the Agave family, a subgroup of flowering plants that also includes grasses and orchids –– so it’s technically not a tree at all. The species grows primarily in the Mojave Desert but can also be found in western Arizona’s Sonoran Desert and parts of Utah and Nevada.
Called “hunuvat chiy’a” or “humwichawa” by local Cahuilla elders fluent in the tribe’s language, the plant’s tough leaves were once used to make baskets, sandals, and thatched roofs. For hundreds of years, the Cahuilla, Mojave, Chemhuevi, and Serrano people relied on the plant’s seeds, flowers, and stems for food. Its fruit is dry and corky but appears in the dietary history of the Death Valley Shoshone.
Miners and ranchers who moved to the area in the 19th century used the leaves to make fencing and the saponin-rich roots to make soap.
Darwin's Darling
Joshua tree reproduction involves two examples of interspecies symbiosis called obligate mutualism. Yucca moths pollinate the tree’s flowers by laying eggs inside the petals. Their larvae feed on the Joshua tree seeds but leave enough behind for the plant to reproduce. Once the seeds have matured, white-tailed antelope ground squirrels dismantle their pods. They eat some of the seeds and disperse the rest.
Charles Darwin called the process the “most wonderful case of fertilization ever published,” but this natural wonder is under threat.
A Staggering Deathtoll
“Zombie forests" are how Stanford researchers characterize the ecosystems of Joshua Tree National Park.
The eerie term may sound like it has something to do with “Yucca Man,” the mythical “missing link”-style manimal several park-goers claim they’ve spotted at various locations around the Mojave since the 1960s.
Or, you might associate zombies with sci-fi lore about park visitors from Venus or park destinations and phenomena with names like Hall of Horrors, Kids of the Black Hole, plutonic intruders, clonal colonies, contact zone, and Planet X.
But the zombies, in this case, are the Joshua trees themselves. According to botanists who study the Mojave, the apocalyptic reference is to sound the alarm about how extreme wildfire risk is for park vegetation.
Such scientific apprehension may seem strange to park-goers treated to anomalous, out-of-season blooms among a species historically dormant until late spring. During these “pulse events,” the yucca blossoms attract naturalists who spatter Instagram with shots of the plant’s foot-long, rosette-patterned clusters of greenish-white petals.
But this is no pretty picture. It’s actually a snapshot of climate change in action.
As weather patterns and environmental factors respond to a warming planet, the yucca adapt by reproducing at unprecedented intervals in last-ditch efforts to save themselves from extinction.
By the end of the century, if the climate clock continues ticking at the pace it is now, scientists warn, there won’t be many twisty succulents still haunting the national and natural treasure bearing their name –– a name, which, by the way, has nothing to do with end times, but is probably a nod to new beginnings.
The Promised Land
Most accounts trace the origins of the plant’s name to mid-19th century Mormon pioneers who thought the yuccas resembled Joshua extending his hands to guide the Israelites toward the promised land or perhaps associated the tree’s spear-shaped leaves with Joshua’s army of Israelites gathering to conquer Canaan.