marijuana, Pharmacology

Related Category: Pharmacology

marijuana or marihuana, drug obtained from the flowering tops, stems, and leaves of the hemp plant, Cannabis sativa (see hemp) or C. indica; the latter species can withstand colder climates. It is one of the most commonly used drugs in the world, following only caffeine, nicotine, and alcoholic beverages in popularity. In the United States, where it is usually smoked, it also has been called weed, grass, pot, or reefer.