May 16, 2020 - 10:11 am
To outsiders, a Joshua tree could look nightmarish and threatening, with its daggerlike spines and odd growth habit, but to most Mojave Desert dwellers it is strikingly beautiful. In the morning light, or under a full moon, the Joshua tree’s silhouette is the definition of drama. And because they grow almost nowhere else, to see one is to know we are home.
Joshua trees grow naturally at an elevation of about 2,000 to 6,000 feet, preferring sandy, dry soils on slopes, mesas and rolling hills.
Joshua trees, Yucca brevifolia, are members of the agave family. Until recently, they were considered large members of the lily family, but DNA studies led to dividing that extensive family into 40 distinct ones. The Joshua tree is the largest of the yuccas, and mature ones range from about 15 to 40 feet tall.
Joshua trees grow only about one-half inch to three inches per year. They are said to typically live about 150 years, but some are thought to be as old as 500 years. Their age is not easy to verify since there are no growth rings as there are in, say, a pine tree.
In spring the tree comes into bloom bearing large bell-shaped, cream-colored flowers in bunches 12 to 18 inches in diameter. Joshua trees have a symbiotic relationship with the yucca moth (Tegeticula yuccasella), also referred to as the pronuba moth, for pollination. The female moth lays her eggs on the flower’s ovaries, and when the larvae hatch, they feed on the plant’s seeds. To start a new Joshua tree the germination of a seed needs the right amount of rain, at the right temperature. In some instances, the plant can also sprout from its roots or branches.
It is said that Mormon pioneers named the tree Joshua, after the Old Testament figure who led the children of Israel in the conquest of Canaan. It seemed to them the outstretched limbs were directing the Mormons forward into another promised land.
Great places to see thick stands of Joshuas are in the Mojave National Preserve and of course at Joshua Tree National Park, both in California. (The latter is closed temporarily.) Also, just west of Searchlight, about 8.2 miles along Nevada Route 164, there is the Wee Thump Joshua Tree Wilderness area on your right, with a nice thick band of them. Dawn is the best time to stroll around, but be wary of wandering, as one Joshua looks much like another when you’re trying to retrace the steps to your car.
While Joshua trees are mostly seen in the Mojave Desert, plants ignore geographic boundaries, so a few can be found in the Sonoran Desert in western Arizona, where they might be growing alongside saguaros. They can sometimes be seen with pines in California’s San Bernardino Mountains.
The Joshua tree was useful to American Indians, who wove baskets and sandals from the strong leaves and ate the flower buds and seeds, both raw and roasted. Miners used the trees to fuel their steam engines, and homesteaders made fences with them.
Many mammals, reptiles, birds and insects depend on the Joshua tree for their habitat, including the Scott’s oriole, which often builds its nests within the trunks and can been found from 3 feet up to 25 feet high.