The Joshua Tree isn't really a tree at all, rather, it is a giant yucca plant. The trunk of a Joshua Tree consists of thousands of small fibers and it lacks annual growth rings, making it difficult to determine it's age. New seedlings can grow up to 3 inches per year in their first ten years. After that they grow only 1 1/2 inches per year.
According to park literature, the Joshua tree was so named by a group of Mormon settlers who crossed the Mojave Desert in the mid-19th century. The tree's unique shape reminded them of a Biblical story in which Joshua reaches his hands up to the sky in prayer.
I was told by a Ranger, that each of the “arms” or the branches of a Joshua Tree was the result of it blooming and flowering. Each bloom creates another branch. The trees bloom in the spring, though they don't all bloom every year. In fact there were some Joshua Trees that were six to eight feet tall without any branches! And then there were other trees with an overabundance of blooms. After flowering, the blossoms drop off, leaving a length of dried stalk. New leaves grow beneath this dead portion, and a new branch begins its growth in another direction. The numerous shapes and sizes of the trees is fascinating.
This was one of the largest Joshua Trees that I saw in the park, perhaps 35 feet high. I don't know what caused it to lose the limb hanging down on the ground but it was somewhat recent damage.
It wasn't the first damage this tree sustained. On the side opposite of the new downed limb was a gaping hole from a loss in the distant past.
It also had one of the most complex branching systems that I saw. It must be very old and is still blooming!