Glyphosate is a tricky word that doesn’t exactly roll off the tongue. It’s not a common point of conversation that people have heard about. But everyone has heard of Roundup. Drive across the United States and you’ll see vast fields with crop labels that say “Roundup Ready.” Glyphosate is the active ingredient in the pervasive herbicide Roundup. Monsanto, its original manufacturer, claims it is a wonder chemical for agriculture that effectively kills essentially all plants, while leaving humans and other animals unscathed. But Monsanto’s argument is fatally flawed.