http://www.whitehousedrugpolicy.gov/drugfact/marijuana/index.html
Office of National Drug Control Policy, The White House
Marijuana is a green, brown, or gray mixture of dried, shredded leaves, stems, seeds, and flowers of the hemp plant (Cannabis sativa). Cannabis is a term that refers to marijuana and other drugs made from the same plant. All forms of cannabis are mind-altering (psychoactive) drugs.