Tribulus Terrestris (Goatshead) — Terribly Evil Plant From Hell

Goatshead or Puncture Vine

Low maintenance groundcover plants that are willing to grow in poor soil with little irrigation are generally quite welcome in most areas.

And the plant pictured certainly looks pretty damned healthy for something growing in hard pack clay and gravel with no water and zero protection from the blazing hot sun.

Better yet, look at how it is spreading so nicely to cover the ground while maintaining an extremely low growth habit. Looks like it might even be a really pleasant ground cover for paths or walkways.

Goatshead or Puncture Vine

Closer inspection reveals that it even has these really pleasant little yellow flowers!

Cute, even! And it is covered in them!

How can anyone not love this plant?

Goatshead or Puncture Vine Detail

But, wait, what is this?

Every one of those little yellow flowers turns into a seed pod. The fruit of the vine, if you will.

And every one of those little seed pods breaks apart into four or five sections, each with quarter inch spikes.

While the spikes are semi-hard when green (hard enough to puncture skin), they turn iron-hard when dry. The design of the little seed pod sections is such that they spikes point up.

How hard are they?

Hard enough to go through bike tires, thin soled shoes, people feet, animal skin, and — even — small car tires.

And they hurt likely bloody hell. Typical to thorns like this, the surface has some kind of irritant on it that causes the puncture wounds to be extremely painful.

Roger and Goatshead

Roger and I have been on a personal vendetta to eliminate this evil plant wherever we find it. It is one of the few plants that I might actually consider using chemicals on.

As you can see in the picture, this ground crawling vine can get to be quite large. That isn’t even the largest one we have eliminated in the area.

Tribulus terrestis is an invasive species that has gained a foothold across most of the warmer climates of the world. It is the bane of bicyclists and open shoed hikers.

Recently, I ran into a nasty patch of it on one of the trails in Cupertino that I ride my bike to work on. Obviously, an infestation of puncture vine along a public walkway can be very painful and unpleasant to folks using said path.

I contacted Cupertino Parks and Recreation and they had the plant eradicated within a day! Very impressive!

Update: As the summer wore on, a couple more sprouts popped up here and there. Cupertino Parks & Rec eliminated them in short order. Clearly, they keep an eye on outbreaks! Nice!



17 Responses to “Tribulus Terrestris (Goatshead) — Terribly Evil Plant From Hell”

  1. Roy says:

    Good on you. There are things I miss about living in California, but after endless flats on certain bike paths, this is not one of them.

  2. John C. Randolph says:

    Where did this plant come from? I take it it’s not native to CA?

    -jcr

  3. Hans says:

    I think we have this plant in our yard (and I live in Florida). What a pain. The prickers sticks to your clothing and you unwittingly carry them into your home, where they can do further damage. 🙁

  4. don delwood says:

    hey bill – don’t forget that for evil plants of any ilk that are around the casa, boiling water is a wonderful “plant-o-cide”. i use this around the concrete and even in the mulch patches.

    oh, and did i mention – boiling water is organic???? (well, not really, it has no CHO, but….)

    later,

    don

  5. Charles says:

    Those pods reminded me of an obscure word: caltrop.

  6. bbum says:

    Good eye — Caltrop is another common name for Puncture Vine.

  7. n[ate]vw says:

    We’ve got those up here in central WA, too. I’ve pulled at least one that was as tall on my 6′ frame as the one on Roger. If a bike salesman here tries to upsell you into resealing tire tubes, it’s for your own good. I think they’ve changed my gait around the house just enough so that I can pull back up when one finds its way under my heel in the living room.

    @don d: Do you think boiling water would also kill the seeds? If not caught early enough, they leave behind a horde of those little “caltrops”.

  8. don delwood says:

    n[ate]vw – i love using the boiling water. promptly kills leafy stuff and stems. but, i seriously doubt there is much pentrating heat to the water, doubt it stays hot enough long enough on a seed (protected by its thickish hull).

  9. Jon Hendry says:

    Looks like something out of the AD&D Monster Manual, like the Piercer (carnivorous pseudo-stalactites that drop on the unwary)

  10. JW says:

    Well if it was only common knowledge that this evil vine was also an aphrodisiac we probably wouldn’t see it growing wild anymore. It would be a sched III drug. Seriously though, if you google it you will see that it is cultivated and sold as a supplement to increase testosterone production in men.

  11. bbum says:

    Yes — I have had to delete a fairly non-stop stream of spam advertising “hardening agents for men” or sports performance enhancement drugs based on Tribulus.

    Of course, there don’t seem to be any legitimate medical studies backing said claims.

  12. Big T says:

    I just found out that goatheads (tribulus) is the stuff you by too boost your natural testosterone but stand on em and they hurt like all F@#k

  13. bbum says:

    There is some debate as to whether or not they do much for testosterone production. Or, at least, whether or not eating them is more effective than standing on ’em and letting the rage flow.

    Evil little buggers.

  14. Sammie says:

    isnt there a plant that is spreading across the u.s.a and it is like easting houses (covering them)and like it started out as a plant that could feed animals and stuff but then it got out of hand and it like started growin every wher?? some1 plzz answer paticularly bbum tthhxxx

  15. bbum says:

    You are most likely referring to Kudzu.

    http://en.wikipedia.org/wiki/Kudzu

  16. Ray says:

    Add alittle russian knapp weed and some russian olives to make your property almost totally useless.

  17. Heiner says:

    Hi bbum, I just borrowed two of your Images for a post on my (cc-by-sa) blog, see here. Thanks a lot for sharing! Cheers, Heiner

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