Here's Why This Plant Grows Super Slow: It Only Grows 3cm a Year

Unlike most flowering plants that attract bees and butterflies, the Joshua tree only mates with the Yucca moth for its entire life, lasting hundreds of years, even 1,000 years.

If you have ever been to the Mojave Desert in the US, you will surely not be able to take your eyes off the Joshua trees with their long, sharp, bayonet-like leaves. Against the barren background of rocks and sand, they stand out as menacing yet enchantingly beautiful.

Is a plant endemic to the American Southwest.

Joshua tree, scientifically known as Yucca brevifolia , grows only in the Mojave Desert, at altitudes of 400-1800m. Because of its long, narrow, hard and sharp leaves, this tree is also known in Spanish as Izote de desierto, meaning "desert dagger".

The Joshua tree is endemic to the American Southwest.

The name Joshua tree was given by the Mormons in the 19th century. The shape of the tree is reminiscent of Joshua, the biblical figure who stood with his hand raised to show the way to the Israelites during the conquest of Canaan.

The Mojave Desert, in addition to being famous for its arid climate and the famous Death Valley, is also home to the world's only Joshua Tree preserve. In addition, the desert is also responsible for sustaining the lives of 1,750-2,000 other plant species.

The name Joshua was given around the 19th century, by the Mormons.

The slowest tree in the world

Climb to over 400m above sea level in the Mojave and you will see a forest of "dagger-leaf" Joshua trees . Each leaf can be 15-35cm long, but only 7-15mm wide, looking exactly like a sharp, dark green bayonet.

Not only are the leaves long and sharp, they also have serrated edges. Interestingly, from February to late April, this spiteful-looking plant produces stunning clusters of flowers. These flowers do not bloom annually. The buds develop depending on the desert's rainfall conditions and the right timing.

Joshua tree flower

Normally, a young Joshua tree will only grow one main shoot. It will not begin to branch out until it is fully grown and ready to flower. However, if the main shoot is damaged for some reason, it will soon sprout a new shoot to replace it.

One special thing about Joshua trees is that they grow extremely slowly . During the first 10 years, a Joshua tree only grows about 3 inches per year. From the 11th year on, they grow even more slowly, only about 1.5 inches per year.

The reason is also because the living environment is too harsh. Because Joshua trees grow in the desert, even though they have successfully dispersed their seeds, they still have to "look to the sky, look to the ground, look to the clouds" before they germinate. Only when they receive a rare rain will the Joshua tree sprout. If any seed is in a hurry to take root before it receives rain, it will never sprout or flower.

Joshua grows very slowly.

But in contrast to the slower-growing trunk, the roots quickly penetrate deep and extend far into the ground. They can extend up to 11m from the base. From these roots, a few baby Joshua trees can also emerge, making the "big family" more and more crowded.

After all, a Joshua tree can live for hundreds of years, even 1,000 years. However, even with age, they don't grow much taller, at most only 15-20m.

A Joshua tree can live for hundreds of years, even 1000 years.

For animals living in the sweltering desert, Joshua trees are a perfect welfare system. Scott's orioles happily build nests in the branches. Mice choose the Joshua tree's base for burrowing. Many other animals rely on its shade to escape the scorching sun.

Only loyal to Yucca moths

Like all flowers with stamens and pistils, Joshua trees need pollinators. However, they attract only one species of moth, the Yucca moth.

Yuccas are not particularly striking looking butterflies. Surprisingly, these moths have evolved tentacle snouts instead of the familiar pointed proboscis. This allows them to easily pollinate Joshua trees. In return, this allows the moths to lay their eggs in the flower ovules. The yucca larvae, after emerging from the egg, will eat the newly formed Joshua fruit.

The reason why Joshua trees, despite the danger, "bet it all" on the Yucca moth is because they are nectarless flowers. Most insects hang around the flowers for the sweet nectar, not for their beautiful appearance. The Yucca moth does not come to Joshua flowers to feed. It comes to lay eggs.

Each Yucca that visits a Joshua tree will use its tentacle-like mouth to roll the pollen into tiny balls.

In fact, without Yucca, Joshua trees would have no way to reproduce. Each Yucca that visits a Joshua tree will use its tentacle-like mouth to roll pollen into tiny balls. It then carries the "pollen balls" to another Joshua tree that has not yet been fertilized by its own kind, and sends the next generation to pollinate the Joshua tree as well.

When the Yucca larvae hatch, they will eat the young Joshua trees. When they mature, they crawl down to the base of the tree, burrow into the ground, spin cocoons, and wait for the next spring to continue the cycle.

As for Joshua, they will devote their energies to nurturing the fruit that is not damaged by the Yucca worm. When the fruit is ripe, the wind or wild animals will help them spread the seeds.