The drug sold as K2, spike, spice or "synthetic marijuana" may look like dried marijuana leaves. But it's really any of a combination of chemicals created in a lab that are then sprayed on dried plant material. Spencer Platt/Getty Images hide caption

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A package of synthetic marijuana, or spike. Steve Featherstone hide caption

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A sign outside a medical marijuana dispensary in Manitou Springs, Colo. Voters amended the state's constitution to legalize marijuana for recreational use in November 2012. Eric Whitney hide caption

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A package of K2, a concoction of dried herbs sprayed with chemicals sometimes called synthetic marijuana. New York moved to ban a wide range of products like these this week. Kelley McCall/AP hide caption

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