Tag Archives: biology

Bon Air Science Fair!

This upcoming Tuesday at 6pm, Bon Air Library will be hosting a program full of science experiments for teens, all supplies provided! Experiments will include Elephant Toothpaste, Silly Putty, Ice Cream, and building a wave machine. Come check it out!

What’s Elephant Toothpaste? Here’s a more extreme demonstration!

Teddy Bear Cholla

Sometimes, names are abject liars, and something that sounds harmless, or actually cute can be horrible. Probably the mascot of all things so much worse than they sound is the downright adorably-named Teddy Bear Cholla ( Cylindropuntia bigelovii ). Even the scientific name of this vegetable horror sounds cute: bigelovii. D’awwww.

Here’s a patch of them:

a patch of teddy bear cholla looking chubby and cute.

By Homer Edward Price (Teddy-Bear-Chollas-c Uploaded by Amada44) [CC BY 2.0 (http://creativecommons.org/licenses/by/2.0)], via Wikimedia Commons

I mean, they even look sort of cute. Nubby and chubby and maybe plush and fuzzy. But it’s not fuzz. It gets worse.

It’s wicked sharp needles.

Closeup of teddy bear cholla needles. Sharp.

Stan Shebs [CC BY-SA 3.0 (http://creativecommons.org/licenses/by-sa/3.0) or CC BY-SA 2.5 (http://creativecommons.org/licenses/by-sa/2.5)], via Wikimedia Commons

Ouch. But wait, it gets even worse. The needles have tiny serrated edges, so that like a harpoon head, once they stick, they’re hard to pull out. By which I mean an entire chunk of cactus is now stuck to you by its spines. Cholla segments are very weakly attached to the rest of the cactus and they break off at the slightest touch.

Teddy Bear Chollas reproduce primarily through this process of harpooning and hitching rides on unfortunate animals, who transport the chunks to new locations until they can finally work the spines out. The cactus chunks can take root where they land, and a new Teddy Bear Cholla is born. They also flower and produce fruit with seeds in it though.

cup-shaped teddy bear cholla blooms.

Quite pretty flowers, actually.

Teddy Bear Chollas, like many plants, can reproduce either sexually (with flowers and pollination) or asexually (cloning via pieces of the plant taking root). Cloning is much faster and more effective, but all the plants that root from pieces of a mother plant are genetically the same, and so all of them share the same vulnerabilities. That’s why genetic diversity in a species is so important. The more different versions of genes are available, the more chances there are to resist any one disease or other threat.

Like So:

A drawing of a patch of cholla, where most are one type, but there's two that don't match the rest.

A Wild Cholla Patch Appears! Most are clones of the mother plant, but a few are from seeds, and have other genes mixed in.

the mother and clones are killed, leaving the different two cholla.

Although the parasite kills the mother plant and the clones, which were vulnerable to it, it doesn’t get the others.

Cholla patch with a mix of the two surviving cholla plants.

And the cholla keep on spreading mostly by cloning, but sometimes by seeds.

Teddy Bear Cholla are very good at spearing and spreading.

Cholla patch spreading out into the far distance.

By Jack Dykinga [CC BY-SA 2.0 (http://creativecommons.org/licenses/by-sa/2.0)], via Wikimedia Commons

This is a (mostly) clone army, stretching out to the far horizon. They feel no remorse or compassion. They know no mercy. Their numberless children are bred on blood and agony… Dang.

Teddy Bear Cholla are METAL.

Fortunately, we live outside their natural range. But, anyway, if you go to the desert Southwest of North America, keep an eye on the Cholla.