One is growing next to a lily plant in my yard. Those in the sun and on flat dirt lie close to the ground. Those where they're getting water stand up.
This has fun close-up photos. Socorro Fat Tire Cycling
Seems innocent, doesn't it? Just a few stray, ground-hugging weeds overgrowing the middle of the road. Nothing to worry about! You've jumped stumps higher than your helmet. You've descended rock-strewn cliffs that would scare a mountain goat. You are not afraid of mere weeds!You . . . will . . . be . . .
Goatheads are basically tetrahedral in shape, meaning that--no matter how they fall to the ground, no matter how they get kicked around--they will always have a spike pointing straight up into your tire. (and there's a photo to go with that)
It's a good cause, if you like to support local musicians and people learning skills just because they want to!