Cannabis. Leaves of the hemp or marijuana plant, Cannabis sativa, which contain an intoxicating drug. The Cannabis plant is native to central Asia. It is cultivated for three products: fibre from the stems, seed oil, and for use as a drug of intoxication. This fast-growing annual plant is a common weed in northern India. In good conditions it can grow to over five metres tall with numerous side branches. Male and female flowers are borne on different plants, the females being most potent. The drug is produced in minute resin glands on the plant surface, including the leaves, but is most concentrated in female flowers. Cannabis is a banned plant in many countries.