Cannabis is a genus of flowering plant in the family Cannabaceae. The number of species within the genus is disputed. Three species may be recognized, Cannabis sativa, Cannabis indica and Cannabis ruderalis; C. ruderalis may be included within C. sativa; or all three may be treated as subspecies of a single species, C. sativa. The genus is indigenous to central Asia and the Indian subcontinent.
Cannabis has long been used for hemp fibre, for hemp oils, for medicinal purposes, and as a recreational drug. Industrial hemp products are made from cannabis plants selected to produce an abundance of fiber. To satisfy the UN Narcotics Convention, some cannabis strains have been bred to produce minimal levels of tetrahydrocannabinol (THC), the principal psychoactive constituent. Many plants have been selectively bred to produce a maximum of THC (cannabinoids), which is obtained by curing the flowers. Various compounds, including hashish and hash oil, are extracted from the plant.
Globally, in 2013, 60,400 kilograms of cannabis were produced legally. In 2014 there were an estimated 182.5 million cannabis users (3.8% of the population aged 15–64). This percentage has not changed significantly between 1998 and 2014.