The seeds are what do the dirty deed.
Here’s a good close-up picture using a quarter for scale.
You can see why they are called “goat heads”.


Notice how many there are.
This was the result of a helpfully-minded eradication attempt
without the proper resources:
when you pluck up the plant (Use rose gloves!) it will drop scores of seeds on the ground!
So be prepared.
Have a “Puncture Vine Kit” handy.

Next Page: a good puncture-vine kit illustrated