I've been wanting to go back to Joshua Tree National Monument (now a National Park) ever since U2 came out with their top-selling album "The Joshua Tree" in 1987.

I had been there during the Summer of 1973 and thoroughly enjoyed it although the two friends that I was traveling with didn't appreciate it as much as I did since we already lived in the South Texas desert.

The Joshua Tree (Yucca brevifolia) is native to Arizona, California, Nevada, and Utah, mainly in the vast Mojave Desert. A group of Mormon settlers crossing the Mojave Desert in the mid-1850s gave the plant its name. The tree's shape reminded them of a biblical story in which Joshua spreads his hand to the sky in prayer.

Joshua trees are relatively fast growers for a desert plant, growing up to three inches per year. Since it is a tree in shape only, its trunk is comprised of thousands of small fibers without annual growth rings. Plants are know to live for hundreds of years, and it's estimated that they can live a thousand years.

The Joshua tree gets top heavy, with branches regularly breaking off and falling to the ground, and has a very deep and extensive root system to more efficiently gather water from the desert environment. They usually bloom from February to April, but blooms are highly dependent on rainfall; little rainfall will mean fewer blossoms, if any. They also need at least one winter freeze in order to bloom. The flowers are pollinated by the yucca moth, and branching occurs at blooms or if the tip of the branch has been damaged by the yucca worm.

Native Americans used the leaves to weave sandals and baskets, and made meals from the seeds and flower buds. Joshua tree trunks were also used by early ranches and miners as fence posts, and for fuel in steam engines.

The Joshua tree is an indicator species for the Mojave Desert. As the Joshua tree goes, so goes the Desert and other wildlife that depend on the Joshua tree for food and shelter.

Current research indicates that the Joshua tree could become extinct in the Desert due to global warming and the extinction of the Shasta ground sloth which apparently was a key to the tree's dispersal.

Following is a short slide show of the park, with more to come this week. If the slide show here doesn't work on your computer, simply click on "View All Images" to watch it at slide.com.

For other programs from The ActiveRain Nature Channel, click here.

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Sources:

1. "A Tree Named Joshua," by Sandra Keith (American Forests magazine)
2. "The Joshua Tree, a Controversial, Contradictory Desert Centurion,"
   by G. Gossard
3. "Wild Lilies, Irises, and Grasses: Gardening With California Monocots,"
   by Nora Harlow and Kristin Jakob