Enacts the "marihuana regulation and taxation act"; relates to the description of marihuana, and the growing of and use of marihuana by persons eighteen years of age or older; makes technical changes regarding the definition of marihuana; relates to the qualification of certain offenses involving marihuana and exempts certain persons from prosecution for the use, consumption, display, production or distribution of marihuana; provides for the licensure of persons authorized to produce, process and sell marihuana; levies an excise tax on certain sales of marihuana; repeals certain provisions of the penal law relating to the criminal sale of marihuana and provisions of the general business law relating to drug paraphernalia; makes an appropriation therefor.