Manipur, June 19 -- Tobacco is the agricultural product of leaves of plants in the genus Nicotiana. All species of Nicotiana contain addictive drug nicotine-a stimulant and sedative contained in all parts of the plants except the seeds-which occurs in varying amounts depending on the species and variety cultivated. The vast majority of commercially available tobacco is derived from the species "Nicotina tabacum", though it is also produced from Nicotiana alata and to a lesser extent Nicotiana cleveandi, Nicotiana longiflora and Nicotiana rustica among others. Nicotiana rustica in particular contains much more nicotine than N-tabacum and other species of nicotiana and forms the basis of a number of unique tobacco products, including severa...