Marijuana - THC (delta-9-tetrahydrocannabinol)
Cannabis is a leafy plant which grows wild in many of the tropic and temperate areas of the world. It is cultivated both indoors and out for the production of its flowering tops. The most commonly used form of cannabis are the leaves and flowering tops (buds) which may be either smoked or eaten; It also comes in a more concentrated resinous form called hashish, and as a sticky black liquid called hash oil. There are three distinct species of cannabis: Cannabis sativa, Cannabis indica, and Cannabis ruderalis, though there is some argument as to whether these should be considered varieties rather than species. Most recreationally used cannabis is the result of interbreeding between these three types. The term 'hemp' is generally used to describe low-thc varieties of cannabis which are grown for industrial uses.