Perusing Ecodefense: A Field Guide to Monkeywrenching I came across a section about how to make a caltrop. A caltrop is an ancient weapon. The Romans called it a tribulus. It looks like this:

Four metal spikes (or two twisted together) in a tetrahedron shape means no matter how you toss it on the ground at least one spike is sticking upwards. Obviously they are for disabling men, animals, or rubber-tired vehicles. Strewn across a road, trail, or pathway they can make life mighty painful or at least terribly inconvenient.

There’s a common plant called caltrop, better known to locals as “puncture vine.” The botanical name is Tribulus terrestris. The fruits of this persistent, ground-hugging, noxious weed are spiky and harden into bicycle tire-hunting demons. They are often called “goatheads.” Anyone who rides a mountain bike can tell you about goatheads. I upgraded to extra-beefy tires and tubes on my bike after too many flats from those things.

The nuisance impact of puncture vine is so great that weevils have been imported and released in order to help control it. The plant originates in southern Europe and the weevils are imported from France as well as India. They lay eggs on the stems and seed pods and the larvae emerge and eat and weaken or kill the plant.

Here’s a picture:

You’ve seen this plant on every roadside!

Here’s what it looks like when the goatheads have launched their assault on your tires:

A weed is a plant you don’t want. Most folks consider Tribulus terrestris to be a weed. Farmers and ranchers know it to be a serious agricultural pest. But some folks are interested in caltrop for its medicinal value.

Yes, the lowly puncture vine, it seems, is an aphrodisiac. The leaves and roots have many (supposed) health benefits. Do a search using the botanical name and you’ll find plenty of stuff about it. I’ve taken herbal supplements that had “alfalfa” as an ingredient. It’s a crazy world out there in supplement-land, you never know what you are getting! So if the herbal way is your thing check out caltrop. Me, I’ll avoid ’em.

p.s. I’m not an eco-warrior or anything like that, I just like reading weird stuff. (That’s my disclaimer if the FBI is reading my blog.)