"Despite its [marijuana's] long history of use and abuse for both medical and recreational purposes, a new generation of synthetic cannabinoids has recently emerged on the market, which are sold on the Internet as herbal mixtures under the brand names of 'Spice,' 'Spice Gold,' 'Spice Diamond,' 'Arctic Spice,' 'Silver,' 'Aroma,' 'K2,' 'Genie,' 'Scene' or 'Dream,' and advertised as incense products, meditation potpourris, bath additives, or air fresheners. These products are often referred to as 'herbal highs' or 'legal highs' because of their legal status and purported natural herbal make-up."

Source

Fattore, Liana and Fratta, Walter, "Beyond THC: the new generation of cannabinoid designer drugs," Frontiers in Behaviorial Neuroscience (Lausanne, Switzerland: September 2011) Volume 5, Article 60, p. 1.