From the CO2Science Archive: Eupatorium adenophorum seems to be universally despised, which may explain why it travels under so many pseudonyms, beginning with its alternative Latin name Ageratina adenophora, and its many common aliases like eupatory, sticky eupatorium, sticky snakeroot, thoroughwort, Crofton weed and, most vividly, Mexican devil. It is toxic to horses and destructively invasive in countries around the world. But like rain and sun, the CO2 fertilization effect falls on the righteous and the unrighteous alike, and in 2012 a series of five experiments showed that an extra 300 ppm CO2 caused Sticky Snakeroot to grow an additional 27.4%. So horse owners beware and connoisseurs of wacky plant names find delight.