Cannabis leaf. Leaf of the marijuana (or hemp) plant (Cannabis sativa), which contains an intoxicating drug. The Cannabis plant is native to central Asia. It is cultivated for its fibrous stems, its seed oil and the drug it contains. This fast-growing annual plant is a common weed in northern India. In good conditions it can grow to over five metres in height 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's surface, including the leaves, but is most concentrated in female flowers. Cannabis is a banned plant in many countries.