Marijuana The purpose of my paper is to prove that marijuana effects teens and their mind. Marijuana is a tobacco-like substance produced by drying the leaves, stems, flower tops of the Cannabis sativa (Indian Hemp) plant (Fact Sheet, 1). It is smoked or eaten to get hallucinated and receive pleasure. It grows just about anywhere. It is illegal in some countries but in others it is used for medical purposes (Encarta, 1). Some names that it is called a joint, nail, pot, Mary Jane, hive, etc. (Fact Sheet and Facts for teens, 1). Marijuana stays in the body for several days after one smoking session. In a chronic user marijuana can stay in the body for up to several week