After reading Rachel Abrahamson's excellent article about goatheads ("The Trouble With Tribulus Terrestris L." BW, July 25, 2007), I was inspired to seek out and destroy any I could find in my alley. Once I got the photo off Wikipedia, I sure found plenty to rip up, and it felt good to do something for my fellow North End cyclists. Rachel mentioned that goatheads are used as an aphrodisiac in some cultures, which has me wondering if they are the same as Horny Goat Weed.
—Elle Kohut, Boise
At the risk of sounding like a biped supremacist, my loathing of goatheads is deeper than any puncture wound. Those little bastards, or their barbed seeds to be precise, have caused me to walk a disabled bicycle more miles than I care to remember. Yanking them out of the ground by their roots is far too good for them; they should suffer as much pain as they cause—if only to avenge the rain-soaked mountain bikers dragging themselves out of the Foothills and all the helpless pups limping around with perforated paws. Anything short of pouring buckets of boiling vinegar on the weeds is just coddling the worthless reprobates. I'm fairly certain there's plenty of case law to support justifiable vegicide.
Murderous feelings notwithstanding, your question is a good one. Though they share erotic reputations and caprine nicknames, the goathead plant and horny goat weed are very different. The target of my scorn is of the genus Tribulus, while horny goat weed goes under the classification Epimedium, and is a much more courteous flowering vine also known as Bishop's Cap. Goatheads, sometimes aptly called puncture vine, flourish in poor, sandy soil but are hearty enough to mine the pathways along most of the balmy regions of the world. They are actually fairly easy to recognize, in late summer, by the single, pea-sized yellow flower growing up from a flat patch of small, furry leaves and tiny vines. Admittedly, the fruit that grows from each flower is kind of cool: It's shaped something like an iron cross, and once dried, breaks apart into five, two-pronged nutlets—each quarter-inch spike capable of instantly turning a shoddily-shod hiker into a lacerated hater.
In Ayurvedic medicine, the traditional Indian system of health, puncture vine gained a reputation as a libido-enhancer and is known to practitioners as goksura. Ayurveda also employs the plant for treatment of hair loss, urinary difficulties and as an all-around energy booster. According to The Encyclopedia of Indian Medicine, crushing those demon seeds in a little goat urine produces a fine remedy for kidney or urinary tract stones. Fortunately, I suppose, kidney stones are agonizing enough to convince a person that drinking a goat urine cocktail might be a good idea. Lest you dismiss the tonic as quickly as I, one modern study has actually shown goksura to be effective against these stones—at least in rats (who, clearly, aren't quite so picky about their beverages).
Western science has also tried to validate the goathead's status as an aphrodisiac—and early studies looked promising: One Bulgarian project indicated that extracts increase testosterone levels and muscle mass in men, and a study in Singapore demonstrated an increase in copulating activity among rats (even castrated ones). News travels fast, so in their usual fashion of premature elaboration, supplement manufacturers quickly added Tribulus to bodybuilding formulas and sexual stimulants. Further investigation with controlled research, however, has clearly shown no effect on strength or muscle mass, and little effect on testosterone beyond the normal range (the jury is still out on erectile enhancement). But one small discovery that might have muscle-heads rethinking the supplement and joining my anti-goathead militia: It just might cause a guy to grow man-breasts.
Apparently, Tribulus has its strongest effect luteinizing hormone (LH), a glycoprotein responsible for the production of both testosterone and estradiol. As the most powerful of the natural estrogens, estradiol is primarily responsible for development of female sex characteristics, like breasts. And, if that possibility doesn't make a chap lose whatever arousal he may enjoy, then the fact that sheep eating the plant often expire from hind limb paralysis and liver pathology probably should.
Furthering a self-serving agenda, might I suggest to those body builders combating sexual frustration to channel it into a worthwhile project like, say, goathead eradication? I'm sure I could find some military research showing that merciless destruction raises testosterone levels and may, therefore, be therapeutic. It also might help me to have some big fellas around in the alley; I'm a little nervous about running into angry bicycle repair guys.