Bloom Blog

The 4 Reasons Why Cacti Have Spines

Alien Planet

I decided to do a morning run a couple weeks ago in Joshua Tree, California. The temperature isn't too hot at sunrise. Nature is scurrying about before finding some shade to settle down and nap during the day. If you've never been to Joshua Tree, you should definitely include it on your bucket list. It's this amazing desert land where the Sonoran and Mojave desert meet. It's almost like you've stumbled in to another dimension and have landed on an alien planet; here you'll find these insane rock formations called Inselburgs. These Inselburgs are massive, yet smooth like stones you would find on a beach as if they had been washed by water for millennia.
And then there are the actual Joshua Trees; the story behind their name origin is fascinating, but I'll summarize it by telling you the good stuff. Mormon's were travelling by caravan looking for Zion; the promised land as promised by Joseph Campbell. They came across this land with rock formations from what looked like an alien planet, and these very strange looking trees who's branches looked like arms reaching towards the sky. Perhaps due to their delirium from hiking through endless amounts of desert, or due to divine inspiration, they said the trees looked like Joshua from the Bible, reaching his hands out towards God. From there, the name stuck and now these crazy alien looking trees are known as Joshua Tree's. 
Back to the morning run; so I'm running through this unfamiliar land, trying to avoid the brush and cacti all around me when all the sudden I look down at my arm, and it's covered in cacti spine.
It took me over an hour to get out all the needles. They had these miniature hooks at the ends that, once it penetrates the skin, is very, very difficult to remove. It made me wonder though; why do cacti have spines in the first place? Well I'm here to tell you the 4 main reasons why that is the case.

1. They Trap Air

Did you know that wind causes evaporation? Well, it does. The air is sucking up water, banking it and storing it for future precipitation. When you're a desert plant, rainfall comes few and far between and so the name of the game is to keep as much water as possible. As odd as it sounds, cacti spines actually help cacti from losing water. The main way that cactus spines prevent cacti from losing water is by reducing air flow around the cactus. The spines break up air flow, which can help reduce evaporation. The trapped air around the cactus can also create a buffer zone with more moist air.

2. They Collect Water

While spines might not be as good as a traditional leaf, they do collect water. The spines have grooves that are actually designed in a special way that catches precipitated air so well that scientists are actually working on a way to replicate this natural technology as a water collection method in drought-stricken areas. They're especially good at catching water from the morning dew or fog, which, for a lot of desert areas is their main source of precipitation.

3. They Provide Shade

The word desert is almost synonymous with heat. When you think of desert you think of a very hot, dry place. As humans, we wouldn't be able to survive the tough conditions of the desert without retreating to some shade during the peak solar hours. Cacti are no different. We all may generate our energy and fuel from the sun, but too much direct sun can lead to radiation burn (aka sunburn). The ridges and grooves, followed by the exterior pins and needles of cacti allow for it's body to be fairly protected by the sun. Every needle counts.

4. They Keep Predators Away

There aren't too many predators that live in the desert. That's because food supply is pretty limited, and cacti are trying to keep it that way... for themselves. One of the most obvious benefits for cacti to have spines is to deter any animal from using it as a food source. If you've ever experienced the pain from getting a bunch of cacti spine on you, you can attest to this fact. Don't get mad at them for this though, they're just trying to stay alive. A recent study shows that 1-in-3 cacti are endangered, so while they may be beautiful to have in your home, take care of them because they could use a helping hand.
So next time you find yourself lost in the desert and you don't have any water, try covering yourself in cacti spine. It'll help trap precipitated air, give you shade, and protect you from any predators. Or, if that doesn't sound appealing maybe just look at the cacti with appreciation that it's designed that with a purpose other than covering your arms and inconveniencing you for an hour while you go for a morning run just for the sake of it.


At Sharebloom, we have a Plant + Cacti monthly subscription where we curate two plants for you every month to choose from to add to your collection. If you're interested, you can find out more here.