cannabis

1 any plant of the genus Cannabis; a coarse bushy annual with palmate leaves and clusters of small green flowers; yields tough fibers and narcotic drugs [syn: hemp]

2 the most commonly used illicit drug; considered a soft drug, it consists of the dried leaves of the hemp plant; smoked or chewed for euphoric effect [syn: marijuana, marihuana, ganja]

see Cannabis

English

Etymology

From cannabis < sc=Grek < קַנַּבּוֹס < קְנֵה בֹּשֶׂם, possibly from word kanubi.

Noun

1. A tall annual dioecious plant (Cannabis sativa), native to central Asia and having alternate, palmately divided leaves and tough bast fibers.
2. Any of several mildly euphoriant, intoxicating hallucinogenic drugs, such as ganja, hashish, or marijuana, prepared from various parts of this plant.

Scientific names

• Cannabis sativa
• Cannabis indica
• Cannabis ruderalis

Translations

Related terms

• dope
• grass
• hemp
• marijuana
• THC
• weed

French

Pronunciation

• /ka.na.bis/, /ka.na.bis/

Noun

fr-noun-unc m

1. cannabis

Spanish

Noun

1. cannabis

See also

• hierba
• marihuana
• mota

Swedish

Noun

cannabis

1. cannabis; Cannabis sativa
2. cannabis; a recreational drug

Cannabis (Cán-na-bis) is a genus of flowering plants that includes three putative species, Cannabis sativa L., Cannabis indica Lam., and Cannabis ruderalis Janisch. These three taxa are indigenous to central Asia and surrounding regions. Cannabis has long been used for fibre (hemp), for medicinal purposes, and as a psychoactive. Industrial hemp products are made from Cannabis plants selected to produce an abundance of fiber and minimal levels of THC (Δ9- tetrahydrocannabinol), one psychoactive molecule that produces the "high" associated with marijuana. The drug consists of dried flowers and leaves of plants selected to produce high levels of THC. Various extracts including hashish and hash oil are also produced. The cultivation and possession of Cannabis for recreational use is outlawed in most countries.

Etymology

The plant name cannabis is from Greek (), via Latin , originally a Scythian or Thracian word, also loaned into Persian as . English hemp (Old English ) may be an early loan (predating Grimm's Law) from the same source. In Hebrew the word is קַנַּבּוֹס [qan:a'bos].

The further origin of the Scythian term is uncertain, although it is possible that it traces back to the Assyrian word 'qunubu' (way to produce smoke) which was used to refer to the plant.

Description

Cannabis is an annual, dioecious, flowering herb. The leaves are palmately compound, with serrate leaflets. The first pair of leaves usually have a single leaflet, the number gradually increasing up to a maximum of about thirteen leaflets per leaf (usually seven or nine), depending on variety and growing conditions. At the top of a flowering plant, this number again diminishes to a single leaflet per leaf. The lower leaf pairs usually occur in an opposite leaf arrangement and the upper leaf pairs in an alternate arrangement on the main stem of a mature plant.

Cannabis usually has imperfect flowers with staminate "male" and pistillate "female" flowers occurring on separate plants, although hermaphroditic plants sometimes occur. Male flowers are borne on loose panicles, and female flowers are borne on racemes. It is not unusual for individual plants to bear both male and female flowers, though these are referred to as 'intersexual' or hermaphroditic rather than monoecious, since staminate and pistillate structures appear at different points on the plant, not within the same flower.

Cannabinoids, terpenoids, and other compounds are secreted by glandular trichomes that occur most abundantly on the floral calyxes and bracts of female plants.

All known strains of Cannabis are wind-pollinated and produce "seeds" that are technically called achenes. Most strains of Cannabis are short day plants, Cannabis is a genus of flowering plant which includes one or more species. The plant is believed to have originated in the mountainous regions just north west of the Himalayas. It is also known as hemp, although this term usually refers to varieties of Cannabis cultivated for non-drug use. Cannabis plants produce a group of chemicals called cannabinoids which produce mental and physical effects when consumed. As a drug it usually comes in the form of dried buds or flowers (marijuana), resin (hashish), or various extracts collectively known as hashish oil. Recent phylogenetic studies based on cpDNA restriction site analysis and gene sequencing strongly suggest that the Cannabaceae arose from within the Celtidaceae clade, and that the two families should be merged to form a single monophyletic group.

Various types of Cannabis have been described, and classified as species, subspecies, or varieties:

• 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 or wild forms of either of the above types.

Cannabis plants produce a unique family of terpeno-phenolic compounds called cannabinoids, which produce the "high" one experiences from smoking marijuana. The two cannabinoids usually produced in greatest abundance are cannabidiol (CBD) and/or Δ9-tetrahydrocannabinol (THC), but only THC is psychoactive. Since the early 1970s, Cannabis plants have been categorized by their chemical phenotype or "chemotype," based on the overall amount of THC produced, and on the ratio of THC to CBD. Although overall cannabinoid production is influenced by environmental factors, the THC/CBD ratio is genetically determined and remains fixed throughout the life of a plant. Non-drug plants produce relatively low levels of THC and high levels of CBD, while drug plants produce high levels of THC and low levels of CBD. When plants of these two chemotypes cross-pollinate, the plants in the first filial (F1) generation have an intermediate chemotype and produce similar amounts of CBD and THC. Female plants of this chemotype may produce enough THC to be utilized for drug production.

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 species. One widely applied criterion for species recognition is that species are "groups of actually or potentially interbreeding natural populations which are reproductively isolated from other such groups." 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. However, physical barriers to gene exchange (such as the Himalayan mountain range) might have enabled Cannabis gene pools to diverge before the onset of human intervention, resulting in speciation. It remains controversial whether sufficient morphological and genetic divergence occurs within the genus as a result of geographical or ecological isolation to justify recognition of more than one species.

Early classifications

The Cannabis genus was first classified using the "modern" system of taxonomic nomenclature by Carolus Linnaeus in 1753, who devised the system still in use for the naming of species. He considered the genus to be monotypic, having just a single species that he named Cannabis sativa L. (L. stands for Linnaeus, and indicates the authority who first named the species). Linnaeus was familiar with European hemp, which was widely cultivated at the time. In 1785, noted evolutionary biologist Jean-Baptiste de Lamarck published a description of a second species of Cannabis, which he named Cannabis indica Lam. Lamarck based his description of the newly named species on plant specimens collected in India. He described C. indica as having poorer fiber quality than C. sativa, but greater utility as an inebriant. 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. However, many taxonomists found these putative species difficult to distinguish. In the early 20th century, the single-species concept was still widely accepted, except in the Soviet Union where Cannabis continued to be the subject of active taxonomic study. The name Cannabis indica was listed in various Pharmacopoeias, and was widely used to designate Cannabis suitable for the manufacture of medicinal preparations.

20th Century

In 1924, Russian botanist D.E. Janichevsky concluded that ruderal 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. This excessive splitting of C. sativa proved too unwieldy, and never gained many adherents.

In the 1970s, the taxonomic classification of Cannabis took on added significance in North America. Laws prohibiting Cannabis in the United States and Canada 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 Dr. Richard E. Schultes and others testified for the defense. The botanists engaged in heated debate (outside of court), and both camps impugned the other's integrity.

In 1976, Canadian botanist Ernest Small and American taxonomist Arthur Cronquist 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.

Professors William Emboden, Loran Anderson, and Harvard botanist Richard E. Schultes and coworkers also conducted taxonomic studies of Cannabis in the 1970s, and concluded that stable morphological 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. According to Schultes' and Anderson's descriptions, C. sativa is tall and laxly branched with relatively narrow leaflets, C. indica is shorter, conical in shape, and has relatively wide leaflets, and C. ruderalis is short, branchless, and grows wild in central Asia. This taxonomic interpretation was embraced by Cannabis aficionados who commonly distinguish narrow-leafed "sativa" drug strains from wide-leafed "indica" drug strains.

Ongoing research

Molecular analytical techniques developed in the late twentieth century are being applied to questions of taxonomic classification. This has resulted in many reclassifications based on evolutionary systematics. Several studies of Random Amplified Polymorphic DNA (RAPD) and other types of genetic markers have been conducted on drug and fiber strains of Cannabis, primarily for plant breeding and forensic purposes. Dutch Cannabis researcher E.P.M. de Meijer and coworkers described some of their RAPD studies as showing an "extremely high" degree of genetic polymorphism between and within populations, suggesting a high degree of potential variation for selection, even in heavily selected hemp cultivars. They also commented that these analyses confirm the continuity of the Cannabis gene pool throughout the studied accessions, and provide further confirmation that the genus comprises a single species.

Karl W. Hillig, a graduate student in the laboratory of long-time Cannabis researcher Paul G. Mahlberg at Indiana University, conducted a systematic investigation of genetic, morphological, and chemotaxonomic variation among 157 Cannabis accessions of known geographic origin, including fiber, drug, and feral populations. In 2004, Hillig and Mahlberg published a chemotaxomic analysis of cannabinoid variation in their Cannabis germplasm collection. They used gas chromatography to determine cannabinoid content and to infer allele frequencies of the gene that controls CBD and THC production, within the studied populations. In his doctoral dissertation published the same year, Hillig stated that principal components analysis of phenotypic (morphological) traits failed to differentiate the putative species, but that canonical variates analysis resulted in a high degree of discrimination of the putative species and infraspecific taxa. Another paper published by Hillig on chemotaxonomic variation in the terpenoid content of the essential oil of Cannabis revealed that several wide-leaflet drug strains in their collection had relatively high levels of certain sesquiterpene alcohols, including guaiol and isomers of eudesmol, that set them apart from the other putative taxa. Hillig concluded that the patterns of genetic, morphological, and chemotaxonomic variation support recognition of C. sativa and C. indica as separate species. He also concluded there is little support to treat C. ruderalis as a separate species from C. sativa at this time, but more research on wild and weedy populations is needed because they were underrepresented in their collection.

As of 2007, most taxonomy web sites continue to list Cannabis as a single species.

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, native range, aroma, and subjective psychoactive characteristics. "Sativa" is the term used to describe the most widespread variety, which is usually tall, laxly branched, and found in warm lowland regions. "Indica" is used to designate shorter, bushier plants adapted to cooler climates and highland environments. "Ruderalis" is the term used to describe 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 phenotypic characteristics of cultivars by categorizing them as "pure indica," "mostly indica," "indica/sativa," "mostly sativa", or "pure sativa."

In September of 2005, New Scientist reported that researchers at the Canberra Institute of Technology had identified a new type of Cannabis based on analysis of mitochondrial and chloroplast DNA. The New Scientist story, which was picked up by many news agencies and web sites, indicated that the research was to be published in the journal Forensic Science International. As of 25 Feb 2007 the article is listed as "in press," and there is no mention in the abstract of "Rasta."

Wild cannabis

Wild C. sativa subsp. indica is mainly confined to hash producing areas such as Afghanistan, and parts of Morocco. In the U.S. wild cannabis can grow wild in mid-west areas such as Kansas and Nebraska. This type is not valued for recreational use and is viewed as a weed by farmers. Wild C. sativa subsp. sativa shows great local variation; for example, in warm places, it can reach heights up to 20 feet (6 m) tall, but in colder climates it can be as short as 1 foot (30 cm) in height. Almost every single flower branch bears a seed. The wild C. sativa subsp. sativa has long, thin and airy buds and a Christmas tree shape structure. Wild C. sativa subsp. indica remains compact and bushy with thick buds for the most part, and is sometimes used by the locals for hashish production. Generally, there are far fewer seeds in wild C. sativa subsp. indica.

In many areas, wild or naturalized populations of Cannabis are considered invasive species, and are often targeted by government-sponsored eradication programmes.

Reproduction

Breeding systems

Cannabis is predominantly dioecious, although many monoecious varieties have been described. Subdioecy (the occurrence of monoecious individuals and dioecious individuals within the same population) is widespread. Many populations have been described as sexually labile. Dioecious varieties are preferred for drug production, where the female plants are preferred. Dioecious varieties are also preferred for textile fiber production, whereas monoecious varieties are preferred for pulp and paper production. It has been suggested that the presence of monoecy can be used to differentiate between licit crops of monoecious hemp and illicit dioecious drug crops. Soon thereafter, Schaffner disputed Hirata's interpretation, and published results from his own studies of sex reversal in hemp, concluding that an X:A system was in use and that furthermore sex was strongly influenced by environmental conditions.

Since the 1920s, a number of sex determination models have been proposed for Cannabis. Ainsworth describes sex determination in the genus as using "an X/autosome dosage type". According to other researchers, no modern karyotype of Cannabis had been published as of 1996. Proponents of the XY system state that Y chromosome is slightly larger than the X, but difficult to differentiate cytologically.

More recently, Sakamoto and various co-authors have used RAPD to isolate several genetic marker sequences that they name Male-Associated DNA in Cannabis (MADC), and which they interpret as indirect evidence of a male chromosome. Several other research groups have reported identification of male-associated markers using RAPD and AFLP. Ainsworth commented on these findings, stating,It is not surprising that male-associated markers are relatively abundant. In dioecious plants where sex chromosomes have not been identified, markers for maleness indicate either the presence of sex chromosomes which have not been distinguished by cytological methods or that the marker is tightly linked to a gene involved in sex determination. Many researchers have suggested that sex in Cannabis is determined or strongly influenced by environmental factors. A PCR-based method for the detection of female-associated DNA polymorphisms by genotyping has been developed.

Various strains of cannabis

Although there are hundreds of strains of cannabis in existence, there are also many rumors and urban legends. Many alleged strains, such as Purple Haze, are very predominant in pop-culture (see right), but the actual existence of many of these strains is uncertain and the slang terms used to refer to these strains do not appear to be used by botanists. Some strains, such as G-13, are acknowledged to be urban legends.

Strains of cannabis:

• Acapulco gold
• BC Bud
• Cinderella 99
• Chocolate Thai
• Panama Red
• G-13
• Kush
• Northern Lights
• Purple Haze
• Quebec Gold
• White Widow

Some of the strains' names, such as Chocolate Thai, popular in the early 1990s due to its supposed high potency, entered the mass culture. For example, Chocolate Thai was adopted as a stage name of a jazz performer, whose album The Real McCoy was released in 2006.. It should be noted, however, that because there is no manufacturing or state control over the process of production of cannabis, many "strains" may in fact be just marketing brands adopted by drug dealers to increase sales.

Aspects of Cannabis production and use

• Medical Cannabis discusses its use as a medication.
• Cannabis (drug) discusses its use as a recreational drug.
• Spiritual use of cannabis discusses sacramental and religious use.
• Hemp discusses its uses as a source of housing, oil, food, fibers, and industrial materials.
• Cannabis (drug) cultivation discusses aspects of cultivation for medicinal and recreational drug purposes
• Legality of cannabis focuses on the law and enforcement aspects of growing, transporting, selling and using cannabis as a drug.
  • Cannabis rescheduling in the United States
  • Drug policy of the Netherlands
• Health issues and the effects of cannabis discusses the pharmacology, physical, and mental effects of Cannabis when used as drug.

Gallery of images

References

See also

• Medical Cannabis
• Cannabis (drug)
• Legality of cannabis by country

Further reading

• Cannabis: A History (2005) Martin Booth ISBN 0-312-32220-8
• UNODC: World Drug Report 2006, Chapter 2: Cannabis: Why We Should Care (2006)
• EMCDDA drugs profile: Cannabis (2007)

External links

wikiquote Cannabis

• International Plant Names Index (IPNI)
• The Endocannabinoid System Network (ECSN) - Contains medical information to the Endocannabinoid System
• Erowid: Cannabis (Marijuana) Vault.