Idaho Weed Awareness Campaign
Home What's New Virtual Field Guide Network Center Background Site Index

VIRTUAL FIELD GUIDE >> Noxious Weed List >> Puncturevine

Puncturevine (Tribulus terrestris)   

Puncturevine rosette.
Puncturevine rosette.
Photo Courtesy of Canyon County Noxious Weed Control

Puncturevine, from the Zygophyllaceae or (Caltrop family) and sometimes better known as a goathead, is a plant designed to survive. From the time the seed sprouts until it blooms and starts to form seed can vary, but usually only takes 2 - 3 weeks. The plant will continue to grow and produce seed until it is stopped. The first freeze will kill the plant in the fall.

The seed is an amazing product of natural selection. The seed coat is extremely durable (as you well know if you've ever stepped on one with a bare foot) and in the right conditions can last upwards of 20 years. Typically 3-7 years is the period most of us are dealing with. Each fruit or burr, from the plant separates into five separate segments. Each segment has two to four seeds inside it. Each of those individual seeds have a varying degree of dormancy. One portion of the seed may be past its prime, but there's a couple more still to come into theirs. So you see, the seed can patiently wait and wait for the right conditions to sprout. The seed is also transported across the country in tires of automobiles and in livestock feed which allows the puncture vine to continue to grow and spread in the US. (From

Puncturevine seed.
Puncturevine seed.

See the Puncturevine Video Sequences

Other Web Resource Links

All content on this web site is licensed under a Creative Commons License.