USA. Colorado state. Denver. Sarah (R) and her husband Shawn smoke a joint during their tourist Cannabis Bus tour. The couple came from Nebraska for a weekend to discover the newly legalized recreational marijuana market. Cannabis, commonly known as marijuana, is a preparation of the Cannabis plant intended for use as a psychoactive drug and as medicine. Pharmacologically, the principal psychoactive constituent of cannabis is tetrahydrocannabinol (THC); it is one of 483 known compounds in the plant, including at least 84 other cannabinoids, such as cannabidiol (CBD), cannabinol (CBN), tetrahydrocannabivarin (THCV), and cannabigerol (CBG). 20.12.2014 © 2014 Didier Ruef