Apple #383: Joshua Trees

All right, I'm back from my trip. And I have many questions, of course. I took a lot of photos with my new camera mainly of plants, so a lot of my questions have to do with plants.

The first plant I encountered which made my jaw drop at its sheer insanity was the Joshua tree. I had no idea what they were when I first saw them and they looked to me like something straight out of The Lorax.


The Lorax and the Truffula trees, which he turns into thneeds. Everyone needs a thneed, right?
(You can get a painting of this image from Tiffany Duening at SprayGraphic)



A stand of Joshua trees, Palmdale, CA. Don't they look a lot like those Truffula trees?
(Photo by the Apple Lady. How exciting that I get to say that!)

All of these photos, by the way, were taken in Palmdale, California, which is in the Mojave Desert.


Apparently, I'm not the only one who confused Joshua trees with something else. They have been misunderstood, reminded people of other things, and mis-named several times.

• Natives who lived in this area for centuries called the tree "hunuvat chiy'a." That's not really a misunderstanding or misnaming, it's just an alternate name.
  

• German immigrants thought they looked like the prophet Joshua praying to God with upraised arms and pointing the Israelites to the Promised land. So they called them Joshua trees.

• Other German settlers who came to the Antelope Valley where lots of these trees grow thought they were date palm trees. So they named the place Palmenthal, which later became Palmdale.
  

• In fact, they're not even trees. They are Yucca plants, which used to be classified as part of the lily family (now they're grouped with Agaves).

• The full Latin name for the Joshua tree is Yucca brevifolia. It is closely related to the Mojave yucca, the Yucca schidigera. The two plants often grow near each other, and they look very similar except the Mojave yucca's leaves are wider and longer, and there are fibrous threads that stick out from the edges of the leaves. I don't think I have any photos of the Mojave yucca, but if any of you plant enthusiasts out there spot a misidentification, please let me know.

Another thing that makes them look weird is the bark. The spines on the top dry up and turn gray as the plant grows, but they don't fall off. They stay shaggy on the trunk. In the photo below, you can see that on the trunk on the left.


Joshua tree trunks.
(Photo by the Apple Lady)

Some of the trunks didn't have that shaggy stuff on them. On the trunk in the foreground, you can plainly see the bark, no shaggy old spines on it. Eventually the shaggy spines drop off, exposing the bark. But based on the fact that I saw so few exposed trunks, I'm guessing it takes a long time for the spines to drop off.


As far as plants go, there are a lot of unusual things about Joshua trees.

• They are monocots, which among other things means they are a flowering plant and the vascular tissue that goes up the stem to feed the plant is scattered throughout the stem, not bundled into a single ring.
  

• This means they don't have growth rings so you can't figure their age that way.
  

• Based on guesses about the growth rate of the plants, some of the oldest trees are estimated to be between 800 and 1,000 years old.

• The old ones can get to be anywhere from 30 to 80 feet tall.

The Joshua tree sticking up was much taller than the others I encountered in the area. I'm really bad at guessing heights and distances, but I put this one at maybe 10 or 12 feet tall. It might be even taller than that, though.
(Photo by the Apple Lady)

• It's rare, though, for the trees to get that tall because of the way they grow. They grow vertically until a blossom starts at the knob-end of the branch. The new growth will veer off to the side and continue from there. That's how they wind up looking all twisty.

The almost right angle turns in the Joshua tree branches are where it has blossomed in the past and the new growth has veered off from there in another direction. To the left of the Joshua tree is a silver cholla cactus.
(Photo by the Apple Lady. That's me!)

• The roots go only about 2 or 3 feet deep underground. But at the end of the roots are large bulbs which act as reservoirs that hold water. The importance of these bulbs and the fragility of the roots are what makes the Joshua tree very difficult to transplant.

• Joshua trees will bloom only if the plants have the right amount of rainwater and if temperatures are right. There is a saying that they bloom only every seven years, but that's only an indication of the fact that blossoming can be very erratic from year to year.

• When the plants do blossom, the buds open only at night and usually only partially, revealing the seed pod at the center.
  

• The terminal blossom only blooms one time and then the core of the blossoms dries up and falls off.

Blossoms at the terminal end of a Joshua tree. The one on the left has partially blossomed. Sometimes the green buds never do open all the way. The pointy one at the top is all done blossoming and will fall off eventually. I don't know if it's unusual or not for one terminal end to have two blossoms on it.
(Photo by the Apple Lady)

• For a long time, scientists thought that only one species of moth pollinated Joshua trees, but it turns out there are actually two, depending on whether the trees grow in the eastern or western part of the range. Still, that's not very many species for the plants to rely on for their propogation.

• The yucca moths fly around at night -- which is when the blossoms are open -- collecting the pollen until they have enough collected to form a sticky ball. The female moth then forces her sticky pollen ball into a flower, fertilizing it, and also injects her eggs. When the eggs become larvae and hatch, they eat some of the seeds within the flowers. Others that they don't eat get blown away to make more trees.

• In addition to the moths, multiple species of birds (including orioles, wrens, owls), animals (lizards, chipmunks, woodrats, snakes) and insects (moths, ants, termites), rely on the Joshua trees, making their homes on or near them or using them for food.

Native folks have found all sorts of uses for Joshua trees.

• They used the pointy part of the spines to sew with.

Close-up of spines on Joshua tree plant. Faintly in the background is another blossom that's finished.
(Photo by the Apple Lady)

• They smashed up the leaves to make a pulp, which they then used as soap, shampoo, or for washing clothes.
  

• They sewed or wove the leaves together make sleeping mats or to make a kind of roofing material that was resilient and waterproof.

• They roasted and ate the buds, which have a very high sugar content and taste sweet.
  

• They ground up the seeds and made them into flour or ate them whole.

• They used the roots to make a tea to treat gonorrhea.
  

• Since some of the smaller root fibers are red, they wove those into their baskets for extra color, or they used the fibers to make red dye.

• They used the cylinder-like trunks like cans to store nuts and berries.
  

The hollowed-out inside of an old Joshua tree stem. It felt pretty fibrous when I picked it up and part of it crumbled and broke away pretty easily. But it's so nicely circular, I can see the desire to store things in there. Also, you can see how there wouldn't be any "rings" to count like in a regular tree.
(Photo by the Apple Lady)


White folks in the late 1800s and early 1900s tried to find commercial uses for Joshua trees. They came up with various get-rich-quick schemes for the trees, but all of them were pretty much dismal failures. I read about these ideas in various print sources at the Palmdale City Library's excellent local history room, but I didn't take good enough notes so I'm a bit fuzzy on the details.

• One guy from San Francisco thought he could sell all kinds of the wood to make paper pulp. So he had a bunch of Chinese laborers chop down acres of Joshua trees. All the wood got loaded onto ships but then either they couldn't get the OK to sail or a storm came up but anyway the wood sat on the ships and got soaked and all the wood spoiled. Thousands of trees had been cut down to no purpose.
  

• Somebody else thought he could make an alcoholic drink from the roots that would taste similar to bitters. So he dug up a lot of roots to make a big batch of the beverage. But "nobody could tolerate it."
  

• Because the bark of the tree absorbed moisture very easily, someone else thought the outer fibers would make terrific wallpaper. So they cut down a bunch more of the trees and experimented with various dyes and solutions. But the fibers soaked up too much moisture, and then it all dried out really fast, which made the bark shrink and it fell off of the wall to which it had been stuck. So no Joshua tree wallpaper.

• For a while, the US government used the wood to make splints and prosthetics during World War I. But the wood turned out to be not as ideal as they'd initially thought and people preferred splints and prosethics made of other materials. So more of the wood went to waste.

• Currently, nobody has any commercial uses for Joshua trees. In fact, the plants are now protected. If anyone wants to dig one up, they have to get permission, pay a fee, and they are required to plant the tree elsewhere. Failure to do any of this will get you a hefty fine.

(Photo by the Apple Lady)

After I hung out with the Joshua trees for a while, they started to seem very friendly. Like families of alien alpacas or something. But mainly families. Above you can see a slightly taller one and many young ones that I thought of as "children" of the older plant. I'm not the only one who sees them as people; one scientist said, "To try to describe the average Joshua tree is a little like trying to describe the average person."

It's nice to know that people are looking out for these plant families.


P.S. Yes, there's also U2's album The Joshua Tree. You can download the whole thing as an MP3 for $9.50 from Amazon.


Sources
National Park Service, Joshua Tree National Park, Joshua Trees
Mary Evelyn Austin, Joshua, My Love, 1987 -- a much better resource than it sounds
Graeme Somerville, San Francisco State University, The Biogeography of the Joshua Tree (Yucca brevifolia), Fall 1999
Geocities (soon to be extinct), Palmdale History
Desert USA, Joshua Trees
Michael Mares, Encyclopedia of Deserts, 1999, pp 315-316.
Jeremy Yoder, Joshua tree genetics suggest coevolutionary divergence, Denim and Tweed, October 2, 2008
Sustainablog, Joshua Trees and America, January 21, 2009
UC Berkeley, Monocots versus Dicots