Many of those vigorous plants that gardeners eradicate with herbicides or by fierce yanking from the soil are actually superfoods

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Called the We'd Eat It Project, and founded by Kathy Voth of Utah State University, it's a method by which young heifers are taught to eat a range of noxious plants - such as distaff and bull thistles - that despoil West Marin's grazing lands.

"Evidently the thistles have good nutrition in them. Once the cows got used to them, they trained their own babies to eat them as well," Rathmann explains. "Eating is a lot about culture, and cows have culture too. For the past 20 years, the people at Utah State where this research was done have been figuring out how animals decide what's palatable and what isn't. If it's nutritious, they come to enjoy the taste."

And so do we, Rathmann says. "If you think about a food you're not sure about but then come to like, as the cows did - well, it's exactly the same for people. Your brain gets messages from your stomach to your body that tells it these foods have good nutrition in them. You'll get good energy. You won't get poisoned."

Article concludes with a couple of weedy recipes.