American federal and state laws present marijuana as a dangerous substance requiring coercive control and forbid private citizens from possessing, selling, or growing it. The differences between marijuana and hemp--a similar but uncontrolled substance in the United States--remain largely social and legal, rather than chemical. These complications present conceptual and practical difficulties for the law, which is structured around neat, mutually exclusive categories. More practically, current forensic tests are incapable of discerning hemp from marijuana because of this legal confusion. This paper investigates the conflicting social, scientific, and legal understandings of marijuana and the potential practical implications of its legal status
