Science Cannabis

Introduction 5world (for a comprehensive review of cannabis botany see Clarke, 1981)It has been cultivated as a multipurpose economic plant for thousands ofyears and through the process of selection for various desirable characteristics,many different cultivated varieties exist —some grown exclusivelyfor their fiber content, others for their content of psychoactivechemicals. All of these varieties, however, are generally classified as asingle species first named in 1735, by the famous Swedish botanist Linnaeus,as Cannabis sativa. The Cannabis plant is a lush, fast-growingannual, which can reach maturity in 60 days when grown indoors underoptimum heat and light conditions, and after 3-5 months in outdoorcultivation. The plant has characteristic finely branched leaves subdividedinto lance shaped leaflets with a saw tooth edge. The woody, angular,hairy stem may reach a height of 15 feet or more under optimumconditions. A smaller more bushy subspecies reaching only 4 feet or so inheight known as Cannabis indica was first described by Lamark and isrecognized by some modern botanists. There is currently much activityamong plant breeders in Holland (where cultivation of the plant for personaluse is legal) and in California (where such cultivation is illegal) toproduce new varieties with increased yields of the psychoactive chemicaldelta-9-tetrahydrocannabinol (THC). The details of the breeding programsare not public, but involve such techniques as the treatment ofcannabis seed with the chemical colchicine to cause the creation of polyploidplants, in which each cell contains multiple sets of chromosomesinstead of the normal single set. Such varieties may have extra vigor andan enhanced production of THC, although they tend to be geneticallyunstable. Other varieties have been obtained by crossing Cannabis sativawith Cannabis indica strains, to yield a number of different hybrids.These strains may not breed true but by selecting the first generation (Flhybrid) seeds of such crosses, plants can be generated with hybrid vigorand enhanced THC production. Particularly favorable genetic strainscan also be propagated vegetatively by cuttings —in this way a singleplant can give rise to thousands of clones with identical genetic makeupto the original. Although the cultivation of cannabis for THC productionis illegal in most Western countries, the Internet carries advertisementsfrom numerous seed companies who offer to supply seeds of as many as