Cannabis. Marijuana or hemp plant Cannabis sativa, which is used for an intoxicating drug. The Cannabis plant is native to central Asia. It is cultivated for fibre from the stems, seed oil, and for use as a drug of intoxication. This fast- growing, annual plant can grow in good conditions to over five metres tall with numerous side branches. Male and female flowers are borne on different plants. The intoxicating 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. Photograph of a hydroponically-grown Cannabis plant.