Knowing about marijuana can help you recognize its use in others, so you can encourage them to seek treatment. Marijuana is a street drug made from the flowers, stems, seeds, and leaves of the hemp plant. It is usually smoked as a cigarette, in a pipe, or in a cigar in which the tobacco has been replaced with marijuana. Marijuana also can be consumed by mixing with foods or brewing into a tea. To learn more about marijuana, take this quiz, based on information from the National Institute on Drug Abuse (NIDA).