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The southwest bike tire massacre

The views expressed are those of the author and are not necessarily those of Scientific American.

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I recently visited Tucson, Arizona and was happy to see a fair amount of people riding bicycles rather than driving through the city’s downtown area. There are wide bike lanes and plenty of racks for parking, and even a monthly street fair where bikers can pick up new and used parts or equipment. All this plus a mostly sunny forecast made Tucson seem like an ideal biking locale, until a friend who lives in the area pointed to the numerous needles and burrs sticking out of his bike tires. “They make it kind of miserable to ride,” he said. “You begin to feel like the plant life in Arizona hates bicycles and the people who ride them.”

puncture plant through bike tire

Most likely, the bike tire massacre was due to the puncture plant, a species that was causing problems in Arizona and California when it was reported on in Scientific American’s September 10, 1921 issue. “Specifically this weed is known as Tribulus Terrestris probably because it spreads tribulation and terror among all owners of inflated-tire vehicles.” The plant is native to Southern Europe and is believed to have spread to the United States via the fleeces of imported sheep.


When the plant matures, its fruit (the burr) splits into 5 sections, each covered in needles. As they scatter, they lay needle face-up, waiting to puncture any tire that dares ride over. Once embedded in the rubber, they are very hard to remove and can stay in the tire for long distances, making it easy for seeds to spread. 

Seeds of puncture plant

“The possibilities for damage from this plant are well illustrated by the experiences of a California motorist who reported 70 punctures in one tire, all due to the puncture vine. In some sections where the puncture plant has become established, one-half of the bicycle tire and approximately one-quarter of the automobile tire punctures result from the spiny burs of this plant which are distributed along the wayside.”

Mowing was attempted to control the growth of the plant, but was ultimately unsuccessful. It is now considered a noxious weed by the USDA and is “restricted” and “controlled” in many states, including Arizona. However, while the puncture plant may seem like nothing but a menace, it has proven to be useful as a weapon when covered in poison while its extract can be turned into a potent male sexual enhancement drug.


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  1. 1. janelj54 12:47 pm 04/29/2011

    It’s not just Arizona, the entire intermountain west is infested with it. The darned things can spread a long way across the ground so even paved street shoulders and bike lanes aren’t always safe. I use a kevlar strip between my bike tires and tubes plus self sealing tubes.

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  2. 2. robert schmidt 5:00 pm 04/30/2011

    Sometimes mother nature can be such a biatch!

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  3. 3. OBagle 11:11 pm 04/30/2011

    The answer to the problem is to import those strange looking umbrella trees from Madagascar and go on a Nazi-like planting campaign along major roads. The shade from those trees should be able to inhibit the puncture plant’s intrusion while giving other wild desert grasses and the like a chance to eventually overtake it.

    Link to this

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