Ecological Outreach ServicesThe Plant We All Love to Hate
“It has these, well, awful thorny things that stick in my dog’s paws, in my tennis shoes, and they HURT! I hate this plant and we pull it out and there it is again!“
Even before you finish explaining what you saw, I know you’re talking about PUNCTURE VINE (Tribulus terrestris) or as it is sometimes referred to, “the DEVIL PLANT!” Another common name for it is “goatheads”.
Puncture Vine does an exquisite job of taking advantage of every situation to spread itself, a characteristic of many nonnative weeds.
You’ve got to hand it to nonnative weeds; they really are good at what they do. They can get around just about anything–herbicides, being dug out, being run over, stepped on, smashed, because the whole time they are being abused, they are spreading themselves around via their seeds, by breaking off and rooting, by shooting up in another place from their root system, by sticking in your sweater or socks, or as in the case of tumbleweed, the entire plant breaks off and just rolls away! You may hate them but gosh darn it, they have evolved with the human species and this is what it is all about–surviving or even taking advantage of–you guessed it! US!
Puncture Vine is an introduced annual noxious weed that like so many of our non-native weeds and grasses, hails from a Mediterranean-type climate. It is in the Zygophyllaceae or “Caltrop” Family. Species from this family are native to Europe, Central Asia, Africa, and Australia. Puncture Vine is toxic to cattle and the spiny capsule that encloses the 3-5 ‘nutlets’ or seeds can cause physical injury (many of us can confirm this). It is considered a “pernicious weed” outside of its native range.
Eliminating any non-native weed requires constant vigilance. Methods include herbicides which in my opinion, are of limited to no value when there are already thousands of seeds in the ground. There is some evidence this plant is herbicide resistant as are so many non-native weeds. Just pulling it out works but do this BEFORE IT SETS SEEDS! Pulling it out after it’s developed it’s little devil heads only HELPS IT! The “devil heads” just break open and release all the seeds. Get the plants as young as possible. Pulling it out can be tough in places where you can’t dig or use a shovel such as next to asphalt or in highly compacted soils/bedrock. You can “drain” the seed bank by removing plants as soon as you recognize them and BEFORE seed set. This may take a few seasons but eventually, there are no more seeds in/on the ground. (You can do this with any weed, if you are patient and conscientious). Portable propane burners apparently work but this is NOT an option in fire country/during fire season; check with local fire department regarding use during the rainy season.
There has been some success with bio-control using weevils that control the plant within its native range (no doubt the two co-evolved). The worry with this is how the weevils may respond outside of their native range. For now, this does not seem to be a concern. If you do obtain them, double check with the California Department of Agriculture to insure you are not bringing in yet another new pest. Puncture Vine Elimination:
http://ipm.ucanr.edu/PMG/PESTNOTES/pn74128.html
I met a man who hates this plant so much, despite that it irritates the hell out of his wife, will stop anywhere he sees it just to pull it out. “He keeps his gloves and shovel in the truck.” It may be driving her nuts but I say a hearty THANK YOU to all you knowledgeable Weed Warriors!! GO FOR IT!
Comments are currently closed.