People from other places often think the iconic Joshua tree is a sort of cactus. It grows in the desert, right? But it's not a cactus. The Joshua tree is a variety of yucca plant and has little in common with cacti but its love for dry climates. The largest ones are very old... some are hundreds, even a thousand, years old. They are often top-heavy, so they have elaborate roots to anchor them in the sandy desert soil.
At first glance they might seem strange, severe, even a little scary. When you see a Joshua tree, you know you're in the Mojave desert -- they don't grow in any other desert anywhere else in the world. (In California, we have both the Mojave and the Sonora deserts, quite distinct from each other. The Great Basin and Chihuahua deserts lie east and north of here in Arizona, Nevada, etc. But the Mojave alone can host Joshua trees; they are the emblem of this desert.)
Becoming familiar with the Mojave, learning to love its austere and careless beauty, one can't help but learn to appreciate, even admire, Joshua trees. They exude a strong and quiet dignity, wise and wizened men of the desert patiently persisting through hard times. And they can seem terrible in their beauty too; this is how they came to be named for the archangel Joshua.
But the Joshua tree's survival as a species is tenuous, and it's not just the old story about industrialization, development and loss of habitat. The Joshua tree suffers an inbuilt fragility in the form of its symbiotic dependency on one solitary species of moth (the "Yucca Moth" or Prodoxidae) to reproduce. The Yucca Moths are obligate pollinators of Joshua Trees, meaning without this one species of pale white moth, no bigger than a pencil eraser, Joshua Trees cannot reproduce. Depending for your species' survival on one insect, and one insect alone, is a vulnerability.
Then there's climate change. You'd think that Joshua trees would like the world to get even hotter, but that's not the case. They only grow in the higher, cooler, moister elevations of the Mojave and as the desert gets warmer and drier, these sentinels of the desert will find less and less terrain to suit them. This is why they don't grow at all in the nearby Sonora desert, drier and hotter as it is. (Of course as the planet gets hotter, if they can get the Yucca moths to move with them, perhaps we'll begin seeing them at the beach in Los Angeles, or growing along Hollywood Boulevard).
Here are a few shots of these trees I've made over the years. I hope my love for them shows through.