Marijuana also called cannabis is a leafy plant, which grows wild in many of the tropic areas of the world. The most commonly used form of cannabis are the leaves and flowering tops called buds which may be either smoked or eaten. It can be also concentrated to form called hashish, and as a sticky black liquid called hash oil. There are three different species of cannabis: Cannabis sativa, Cannabis indica, and Cannabis ruderalis. The power of cannabis is different from one variety to another. Some requires only small amount of drug to re ....