Cannabis

The genus Cannabis was formerly placed in the family () or family (), and later, along with the genus (), in a separate family, the family (Cannabaceae ). studies based on analysis and strongly suggest that the Cannabaceae sensu stricto arose from within the former family Celtidaceae, and that the two families should be merged to form a single family, the .

Various types of Cannabis have been described, and variously classified as , , or :[50]

• plants cultivated for fiber and seed production, described as low-intoxicant, non-drug, or fiber types.


• plants cultivated for drug production, described as high-intoxicant or drug types.


• escaped, hybridised, or wild forms of either of the above types.

Cannabis plants produce a unique family of terpeno-phenolic compounds called cannabinoids, some of which produce the "high" which may be experienced from consuming marijuana. There are 483 identifiable chemical constituents known to exist in the cannabis plant, The two cannabinoids usually produced in greatest abundance are cannabidiol (), but only THC is psychoactive. or "chemotype", based on the overall amount of THC produced, and on the ratio of THC to CBD. production is influenced by environmental factors, the THC/CBD ratio is genetically determined and remains fixed throughout the life of a plant.[55]

Whether the drug and non-drug, cultivated and wild types of Cannabis constitute a single, highly variable species, or the genus is polytypic with more than one species, has been a subject of debate for well over two centuries. This is a contentious issue because there is no universally accepted definition of a . Populations that are physiologically capable of interbreeding, but morphologically or genetically divergent and isolated by geography or ecology, are sometimes considered to be separate species. are not known to occur within Cannabis, and plants from widely divergent sources are interfertile. It remains controversial whether sufficient morphological and occurs within the genus as a result of geographical or ecological isolation to justify recognition of more than one species.[61]

Early classifications

The genus Cannabis was first using the "modern" system of taxonomic by in 1753, who devised the system still in use for the naming of species. published a description of a second species of Cannabis, which he named Cannabis indica Lam.. Additional Cannabis species were proposed in the 19th century, including strains from China and Vietnam (Indo-China) assigned the names Cannabis chinensis Delile, and Cannabis gigantea Delile ex Vilmorin. where Cannabis continued to be the subject of active taxonomic study. The name Cannabis indica was listed in various , and was widely used to designate Cannabis suitable for the manufacture of medicinal preparations.[65]

20th century

In 1924, Russian botanist D.E. Janichevsky concluded that Cannabis in central Russia is either a variety of C. sativa or a separate species, and proposed C. sativa L. var. ruderalis Janisch, and Cannabis ruderalis Janisch, as alternative names. assigned wild or feral populations of Cannabis in Afghanistan to C. indica Lam. var. kafiristanica Vav., and ruderal populations in Europe to C. sativa L. var. spontanea Vav. In 1940, Russian botanists Serebriakova and Sizov proposed a complex classification in which they also recognized C. sativa and C. indica as separate species. Within C. sativa they recognized two subspecies: C. sativa L. subsp. culta Serebr. (consisting of cultivated plants), and C. sativa L. subsp. spontanea (Vav.) Serebr. (consisting of wild or feral plants). Serebriakova and Sizov split the two C. sativa subspecies into 13 varieties, including four distinct groups within subspecies culta. However, they did not divide C. indica into subspecies or varieties.

In the 1970s, the taxonomic classification of Cannabis took on added significance in North America. Laws prohibiting Cannabis in the and specifically named products of C. sativa as prohibited materials. Enterprising attorneys for the defense in a few drug busts argued that the seized Cannabis material may not have been C. sativa, and was therefore not prohibited by law. Attorneys on both sides recruited botanists to provide expert testimony. Among those testifying for the prosecution was Dr. Ernest Small, while and others testified for the defense. The botanists engaged in heated debate (outside of court), and both camps impugned the other's integrity. The defense attorneys were not often successful in winning their case, because the intent of the law was clear.[67]

In 1976, Canadian botanist Ernest Small published a taxonomic revision that recognizes a single species of Cannabis with two subspecies: C. sativa L. subsp. sativa, and C. sativa L. subsp. indica (Lam.) Small & Cronq. for traits that enhance fiber or seed production, whereas C. sativa subsp. indica was primarily selected for drug production. Within these two subspecies, Small and Cronquist described C. sativa L. subsp. sativa var. spontanea Vav. as a wild or escaped variety of low-intoxicant Cannabis, and C. sativa subsp. indica var. kafiristanica (Vav.) Small & Cronq. as a wild or escaped variety of the high-intoxicant type. This classification was based on several factors including interfertility, chromosome uniformity, chemotype, and numerical analysis of characters.[69]

Professors William Emboden, Loran Anderson, and Harvard botanist and coworkers also conducted taxonomic studies of Cannabis in the 1970s, and concluded that stable differences exist that support recognition of at least three species, C. sativa, C. indica, and C. ruderalis. For Schultes, this was a reversal of his previous interpretation that Cannabis is monotypic, with only a single species.. This taxonomic interpretation was embraced by Cannabis aficionados who commonly distinguish narrow-leafed "sativa" from wide-leafed "indica" strains.[75]

Continuing research

developed in the late 20th century are being applied to questions of taxonomic classification. This has resulted in many reclassifications based on . Several studies of Random Amplified Polymorphic DNA () and other types of genetic markers have been conducted on drug and fiber strains of Cannabis, primarily for and forensic purposes. They also commented that these analyses confirm the continuity of the Cannabis throughout the studied accessions, and provide further confirmation that the genus consists of a single species, although theirs was not a systematic study per se.

An investigation of genetic, morphological, and variation among 157 Cannabis accessions of known geographic origin, including fiber, drug, and feral populations showed cannabinoid variation in Cannabis . The patterns of cannabinoid variation support recognition of C. sativa and C. indica as separate species, but not C. ruderalis.. Narrow-leaflet and wide-leaflet drug accessions, southern and eastern Asian hemp accessions, and feral Himalayan populations were assigned to C. indica. In 2005, a of the same set of accessions led to a three-species classification, recognizing C. sativa, C. indica, and (tentatively) C. ruderalis. content of the of Cannabis revealed that several wide-leaflet drug strains in the collection had relatively high levels of certain alcohols, including guaiol and isomers of eudesmol, that set them apart from the other putative taxa.[80] The patterns of genetic, morphological, and chemotaxonomic variation support recognition of C. sativa and C. indica as separate species, C. ruderalis is a separate species from C. sativa.

Despite advanced analytical techniques, much of the cannabis used recreationally is inaccurately classified. One laboratory at the found that Jamaican Lamb's Bread, claimed to be 100% sativa, was in fact almost 100% indica (the opposite strain).) may help spur private-sector research, especially in terms of diversification of strains. It should also improve classification accuracy for cannabis used recreationally. Legalization coupled with Canadian government (Health Canada) oversight of production and labelling will likely result in more—and more accurate—testing to determine exact strains and content. Furthermore, the rise of craft cannabis growers in Canada should ensure quality, experimentation/research, and diversification of strains among private-sector producers.[82]

Popular usage

The scientific debate regarding taxonomy has had little effect on the terminology in widespread use among cultivators and users of drug-type Cannabis. Cannabis aficionados recognize three distinct types based on such factors as morphology, , aroma, and subjective psychoactive characteristics. Sativa is the most widespread variety, which is usually tall, laxly branched, and found in warm lowland regions. Indica designates shorter, bushier plants adapted to cooler climates and highland environments. Ruderalis is the informal name for the short plants that grow wild in Europe and Central Asia.

Breeders, seed companies, and cultivators of drug type Cannabis often describe the ancestry or gross characteristics of by categorizing them as "pure indica", "mostly indica", "indica/sativa", "mostly sativa", or "pure sativa".

Cannabis is used for a wide variety of purposes.

History

The use of cannabis as a mind-altering drug has been documented by archaeological finds in prehistoric societies in Eurasia and Africa.'s reference to the central Eurasian taking cannabis steam baths. records, "The Scythians, as I said, take some of this hemp-seed [presumably, flowers], and, creeping under the felt coverings, throw it upon the red-hot stones; immediately it smokes, and gives out such a vapour as no Greek vapour-bath can exceed; the Scyths, delighted, shout for joy."[85] Classical Greeks and Romans also used cannabis.

In China, the psychoactive properties of cannabis are described in the (3rd century AD)., who burned them in incense burners.[86]

In the Middle East, use spread throughout the Islamic empire to North Africa. In 1545, cannabis spread to the western hemisphere where Spaniards imported it to Chile for its use as fiber. In North America, cannabis, in the form of hemp, was grown for use in rope, clothing and paper.

Recreational use