Cannabis (//) is a genus of flowering plant that includes three species (and seven taxa) or subspecies, sativa, indica, and ruderalis. The plant is indigenous to central Asia and the Indian subcontinent.
Cannabis has long been used for hemp fibre, for hemp oils, for medicinal purposes, and as a recreational drug. Industrial hemp products are made from cannabis plants selected to produce an abundance of fiber. To satisfy the UN Narcotics Convention, some cannabis strains have been bred to produce minimal levels of tetrahydrocannabinol (THC), the principal psychoactive constituent. Many plants have been selectively bred to produce a maximum of THC (cannabinoids), which is obtained by curing the flowers. Various compounds, including hashish and hash oil, are extracted from the plant.
Globally, in 2013, 60,400 kilograms of cannabis were produced legally. In 2013 between 128 and 232 million people are thought to have used cannabis as a recreational drug (2.7% to 4.9% of the global population between the ages of 15 and 65).
- 1 Description
- 2 Uses
- 3 Reproduction
- 4 Etymology
- 5 See also
- 6 References
- 7 Further reading
- 8 External links
Cannabis is an annual, dioecious, flowering herb. The leaves are palmately compound or digitate, 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.
The leaves have a peculiar and diagnostic venation pattern that enables persons poorly familiar with the plant to distinguish a cannabis leaf from unrelated species that have confusingly similar leaves (see illustration). As is common in serrated leaves, each serration has a central vein extending to its tip. However, the serration vein originates from lower down the central vein of the leaflet, typically opposite to the position of, not the first notch down, but the next notch. This means that on its way from the midrib of the leaflet to the point of the serration, the vein serving the tip of the serration passes close by the intervening notch. Sometimes the vein will actually pass tangent to the notch, but often it will pass by at a small distance, and when that happens a spur vein (occasionally a pair of such spur veins) branches off and joins the leaf margin at the deepest point of the notch. This venation pattern varies slightly among varieties, but in general it enables one to tell Cannabis leaves from superficially similar leaves without difficulty and without special equipment. Tiny samples of Cannabis plants also can be identified with precision by microscopic examination of leaf cells and similar features, but that requires special expertise and equipment.
The plant is believed to have originated in the mountainous regions northwest of the Himalayas. It is also known as hemp, although this term is often used to refer only to varieties of Cannabis cultivated for non-drug use.
Cannabis normally has imperfect flowers, with staminate "male" and pistillate "female" flowers occurring on separate plants. It is not unusual, however, for individual plants to bear both male and female flowers. Although monoecious plants are often referred to as "hermaphrodites", true hermaphrodites (which are less common) bear staminate and pistillate structures on individual flowers, whereas monoecious plants bear male and female flowers at different locations on the same plant. Male flowers are normally borne on loose panicles, and female flowers are borne on racemes. "At a very early period the Chinese recognized the Cannabis plant as dioecious", and the (c. 3rd century BCE) Erya dictionary defined xi 枲 "male Cannabis" and fu 莩 (or ju 苴) "female Cannabis".
All known strains of Cannabis are wind-pollinated and the fruit is an achene. Most strains of Cannabis are short day plants, with the possible exception of C. sativa subsp. sativa var. spontanea (= C. ruderalis), which is commonly described as "auto-flowering" and may be day-neutral.
Biochemistry and drugs
Cannabis plants produce a group of chemicals called cannabinoids, which produce mental and physical effects when consumed.
Cannabinoids, terpenoids, and other compounds are secreted by glandular trichomes that occur most abundantly on the floral calyxes and bracts of female plants. As a drug it usually comes in the form of dried flower buds (marijuana), resin (hashish), or various extracts collectively known as hashish oil. In the early 20th century, it became illegal in most of the world to cultivate or possess Cannabis for sale or personal use.
Chromosomes and genome
Cannabis, like many organisms, is diploid, having a chromosome complement of 2n=20, although polyploid individuals have been artificially produced. The first genome sequence of Cannabis, which is estimated to be 820 Mb in size, was published in 2011 by a team of Canadian scientists.
The genus Cannabis was formerly placed in the Nettle (Urticaceae) or Mulberry (Moraceae) family, and later, along with the Humulus genus (hops), in a separate family, the Hemp family (Cannabaceae sensu stricto). Recent phylogenetic studies based on cpDNA restriction site analysis and gene sequencing strongly suggest that the Cannabaceae sensu stricto arose from within the former Celtidaceae family, and that the two families should be merged to form a single monophyletic family, the Cannabaceae sensu lato.
- 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" one experiences from consuming marijuana. There are 483 identifiable chemical constituents known to exist in the cannabis plant, and at least 85 different cannabinoids have been isolated from the plant. 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. Physiological barriers to reproduction are not known to occur within Cannabis, and plants from widely divergent sources are interfertile. 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.
History of cannabis
Cannabis sativa appears naturally in many tropical and humid parts of the world. Its use as a mind-altering drug has been documented by archaeological finds in prehistoric societies in Euro-Asia and Africa.
The oldest written record of cannabis usage is the Greek historian Herodotus's reference to the central Eurasian Scythians taking cannabis steam baths. His (c. 440 BCE) Histories 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 Grecian vapour-bath can exceed; the Scyths, delighted, shout for joy." Classical Greeks and Romans were using cannabis, while 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.
The Cannabis genus was first classified using the "modern" system of taxonomic nomenclature by Carl 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.
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. In 1929, renowned plant explorer Nikolai Vavilov 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. 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. The defense attorneys were not often successful in winning their case, because the intent of the law was clear.
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. The authors hypothesized that the two subspecies diverged primarily as a result of human selection; C. sativa subsp. sativa was presumably selected 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 phenotypic characters.
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.
Molecular analytical techniques developed in the late 20th 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, although theirs was not a systematic study per se.
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 chemotaxonomic 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, and concluded that the patterns of cannabinoid variation support recognition of C. sativa and C. indica as separate species, but not C. ruderalis. The authors assigned fiber/seed landraces and feral populations from Europe, central Asia, and Asia Minor to C. sativa. Narrow-leaflet and wide-leaflet drug accessions, southern and eastern Asian hemp accessions, and feral Himalayan populations were assigned to C. indica. In 2005, Hillig published a genetic analysis of the same set of accessions (this paper was the first in the series, but was delayed in publication), and proposed a three-species classification, recognizing C. sativa, C. indica, and (tentatively) C. ruderalis. 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 in the series on chemotaxonomic variation in the terpenoid content of the essential oil of Cannabis revealed that several wide-leaflet drug strains in the 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.
In September 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.
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 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 phenotypic characteristics of cultivars by categorizing them as "pure indica", "mostly indica", "indica/sativa", "mostly sativa", or "pure sativa".
Cannabis is used for a wide variety of purposes.
Cannabis is a popular recreational drug around the world, only behind alcohol, caffeine and tobacco. In the United States alone, it is believed that over 100 million Americans have tried cannabis, with 25 million Americans having used it within the past year.
The psychoactive effects of cannabis are known to have a biphasic nature. Primary psychoactive effects include a state of relaxation, and to a lesser degree, euphoria from its main psychoactive compound, tetrahydrocannabinol. Secondary psychoactive effects, such as a facility for philosophical thinking, introspection and metacognition have been reported among cases of anxiety and paranoia. Finally, the tertiary psychoactive effects of the drug cannabis, can include an increase in heart rate and hunger, believed to be caused by 11-OH-THC, a psychoactive metabolite of THC produced in the liver.
Normal cognition is restored after approximately three hours for larger doses via a smoking pipe, bong or vaporizer. However, if a large amount is taken orally the effects may last much longer. After 24 hours to a few days, minuscule psychoactive effects may be felt, depending on dosage, frequency and tolerance to the drug.
Cannabidiol (CBD), which has no psychotropic effects by itself (although sometimes showing a small stimulant effect, similar to caffeine), attenuates, or reduces the higher anxiety levels caused by THC alone.
According to Delphic analysis by British researchers in 2007, cannabis has a lower risk factor for dependence compared to both nicotine and alcohol. However, everyday use of Cannabis can in some cases be correlated with psychological withdrawal symptoms such as irritability and insomnia, and evidence could suggest that if a user experiences stress, the likeliness of getting a panic attack increases because of an increase of THC metabolites. However, cannabis withdrawal symptoms are typically mild and are never life-threatening.
Medical cannabis (or medical marijuana) refers to the use of cannabis and its constituent cannabinoids, to treat disease or improve symptoms. Cannabis is used to reduce nausea and vomiting during chemotherapy, to improve appetite in people with HIV/AIDS, and to treat chronic pain and muscle spasms.
Short-term use increases both minor and major adverse effects. Common side effects include dizziness, feeling tired, vomiting, and hallucinations. Long-term effects of cannabis are not clear. Concerns including memory and cognition problems, risk of addiction, schizophrenia in young people, and the risk of children taking it by accident.
Industrial use (Hemp)
The term hemp is used to name the durable soft fiber from the Cannabis plant stem (stalk). Cannabis sativa cultivars are used for fibers due to their long stems; Sativa varieties may grow more than six metres tall. However, hemp can refer to any industrial or foodstuff product that is not intended for use as a drug. Many countries regulate limits for psychoactive compound (THC) concentrations in products labeled as hemp.
Cannabis for industrial uses is valuable in tens of thousands of commercial products, especially as fibre ranging from paper, cordage, construction material and textiles in general, to clothing. Hemp is stronger and longer-lasting than cotton. It also is a useful source of foodstuffs (hemp milk, hemp seed, hemp oil) and biofuels. Hemp has been used by many civilizations, from China to Europe (and later North America) during the last 12,000 years. In modern times novel applications and improvements have been explored with modest commercial success.
Ancient and religious uses
The Cannabis plant has a history of medicinal use dating back thousands of years across many cultures. The Yanghai Tombs, a vast ancient cemetery (54 000 m2) situated in the Turfan district of the Xinjiang Uyghur Autonomous Region of the People's Republic of China, have revealed the 2700-year-old grave of a shaman. He is thought to have belonged to the Jushi culture recorded in the area centuries later in the Hanshu, Chap 96B. Near the head and foot of the shaman was a large leather basket and wooden bowl filled with 789g of cannabis, superbly preserved by climatic and burial conditions. An international team demonstrated that this material contained tetrahydrocannabinol, the psychoactive component of cannabis. The cannabis was presumably employed by this culture as a medicinal or psychoactive agent, or an aid to divination. This is the oldest documentation of cannabis as a pharmacologically active agent.
Settlements which date from c. 2200–1700 BCE in the Bactria and Margiana contained elaborate ritual structures with rooms containing everything needed for making drinks containing extracts from poppy (opium), hemp (cannabis), and ephedra (which contains ephedrine).
"While we have no evidence of the use of ephedra among the steppe tribes, we have already seen that they did share in the cultic use of hemp, a practice that ranged from Romania east to the Yenisei River from at least the 3rd millennium BC onwards where its use was later encountered in the apparatus for smoking hemp found at Pazyryk."
Cannabis is first referred to in Hindu Vedas between 2000 and 1400 BCE, in the Atharvaveda. By the 10th century CE, it has been suggested that it was referred to by some in India as "food of the gods". Cannabis use eventually became a ritual part of the Hindu festival of Holi.
In Buddhism, cannabis is generally regarded as an intoxicant and may be a hindrance to development of meditation and clear awareness. In ancient Germanic culture, Cannabis was associated with the Norse love goddess, Freya. An anointing oil mentioned in Exodus is, by some translators, said to contain Cannabis. Sufis have used Cannabis in a spiritual context since the 13th century CE.
In modern times the Rastafari movement has embraced Cannabis as a sacrament. Elders of the Ethiopian Zion Coptic Church, a religious movement founded in the United States in 1975 with no ties to either Ethiopia or the Coptic Church, consider Cannabis to be the Eucharist, claiming it as an oral tradition from Ethiopia dating back to the time of Christ. Like the Rastafari, some modern Gnostic Christian sects have asserted that Cannabis is the Tree of Life. Other organized religions founded in the 20th century that treat Cannabis as a sacrament are the THC Ministry, Cantheism, the Cannabis Assembly and the Church of Cognizance. Rastafarians tend to be among the biggest consumers of modern Cannabis use.
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.
As a result of intensive selection in cultivation, Cannabis exhibits many sexual phenotypes that can be described in terms of the ratio of female to male flowers occurring in the individual, or typical in the cultivar. Dioecious varieties are preferred for drug production, where the female flowers are used. 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 licit crops of monoecious hemp from illicit drug crops. However, sativa strains often produce monoecious individuals, probably as a result of inbreeding.
Cannabis has been described as having one of the most complicated mechanisms of sex determination among the dioecious plants. Many models have been proposed to explain sex determination in Cannabis.
Based on studies of sex reversal in hemp, it was first reported by K. Hirata in 1924 that an XY sex-determination system is present. At the time, the XY system was the only known system of sex determination. The X:A system was first described in Drosophila spp in 1925. 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 then, many different types of sex determination systems have been discovered, particularly in plants. Dioecy is relatively uncommon in the plant kingdom, and a very low percentage of dioecious plant species have been determined to use the XY system. In most cases where the XY system is found it is believed to have evolved recently and independently.
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".
The question of whether heteromorphic sex chromosomes are indeed present is most conveniently answered if such chromosomes were clearly visible in a karyotype. Cannabis was one of the first plant species to be karyotyped; however, this was in a period when karyotype preparation was primitive by modern standards (see History of Cytogenetics). Heteromorphic sex chromosomes were reported to occur in staminate individuals of dioecious "Kentucky" hemp, but were not found in pistillate individuals of the same variety. Dioecious "Kentucky" hemp was assumed to use an XY mechanism. Heterosomes were not observed in analyzed individuals of monoecious "Kentucky" hemp, nor in an unidentified German cultivar. These varieties were assumed to have sex chromosome composition XX. 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."
Environmental sex determination is known to occur in a variety of species. Many researchers have suggested that sex in Cannabis is determined or strongly influenced by environmental factors. Ainsworth reviews that treatment with auxin and ethylene have feminizing effects, and that treatment with cytokinins and gibberellins have masculinizing effects. It has been reported that sex can be reversed in Cannabis using chemical treatment. A PCR-based method for the detection of female-associated DNA polymorphisms by genotyping has been developed.
The word cannabis is from Greek κάνναβις (kánnabis) (see Latin cannabis), which was originally Scythian or Thracian. It is related to the Persian kanab, the English canvas and possibly even to the English hemp (Old English hænep). In modern Hebrew, קַנַּבּוֹס qannabōs (modern pronunciation: [kanaˈbos]) is used but there are those who have theorized that it was referred to in antiquity as קני בושם q'nei bosem, a component of the biblical anointing oil. Old Akkadian qunnabtu, Neo-Assyrian and Neo-Babylonian qunnabu were used to refer to the plant meaning "a way to produce smoke."
- Geoffrey William Guy; Brian Anthony Whittle; Philip Robson (2004). The Medicinal Uses of Cannabis and Cannabinoids. Pharmaceutical Press. pp. 74–. ISBN 978-0-85369-517-2.
- Karl Hillig (January 2005). "Genetic evidence for speciation in Cannabis (Cannabaceae)" (PDF). Researchgate. Retrieved 24 October 2015.
- "Cannabis sativa information from NPGS/GRIN". www.ars-grin.gov. Retrieved 13 July 2008.
- A. ElSohly, Mahmoud (2007). Marijuana and the Cannabinoids. Humana Press. p. 8. ISBN 1-58829-456-0. Retrieved 2 May 2011.
- Erowid. 2006. Cannabis Basics. Retrieved on 25 February 2007
- Narcotic Drugs 2014 (pdf). INTERNATIONAL NARCOTICS CONTROL BOARD. 2015. p. 21. ISBN 9789210481571.
- "Status and Trend Analysis of Illict [sic] Drug Markets". World Drug Report 2015 (pdf). Retrieved 26 June 2015.
- "Leaf Terminology (Part 1)". Waynesword.palomar.edu. Retrieved 17 February 2011.
- Watt, John Mitchell; Breyer-Brandwijk, Maria Gerdina: The Medicinal and Poisonous Plants of Southern and Eastern Africa 2nd ed Pub. E & S Livingstone 1962
- Lebel-Hardenack, Sabine; Grant, Sarah R. (1997). "Genetics of sex determination in flowering plants". Trends in Plant Science. 2 (4): 130–6. doi:10.1016/S1360-1385(97)01012-1.
- Moliterni, V. M. Cristiana; Cattivelli, Luigi; Ranalli, P.; Mandolino, Giuseppe (2004). "The sexual differentiation of Cannabis sativa L.: A morphological and molecular study". Euphytica. 140: 95–106. doi:10.1007/s10681-004-4758-7.
- Bouquet, R. J. 1950. Cannabis. United Nations Office on Drugs and Crime. Retrieved on 23 February 2007
- Li Hui-Lin (1973). "The Origin and Use of Cannabis in Eastern Asia: Linguistic-Cultural Implications", Economic Botany 28.3: 293–301, p. 294.
- 13/99 and 13/133. In addition, 13/98 defined fen 蕡 "Cannabis inflorescence" and 13/159 bo 薜 "wild Cannabis".
- Clarke, Robert C. 1991. Marijuana Botany, 2nd ed. Ron Publishing, California. ISBN 0-914171-78-X[page needed]
- Small, Ernest (1975). "Morphological variation of achenes of Cannabis". Canadian Journal of Botany. 53 (10): 978–87. doi:10.1139/b75-117.
- Mahlberg Paul G.; Soo Kim Eun (2001). "THC (tetrahyrdocannabinol) accumulation in glands of Cannabis (Cannabaceae)". The Hemp Report. 3 (17).
- Small, Ernest (1972). "Interfertility and chromosomal uniformity in Cannabis". Canadian Journal of Botany. 50 (9): 1947–9. doi:10.1139/b72-248.
- Van Bakel, Harm; Stout, Jake M; Cote, Atina G; Tallon, Carling M; Sharpe, Andrew G; Hughes, Timothy R; Page, Jonathan E (2011). "The draft genome and transcriptome of Cannabis sativa". Genome Biology. 12 (10): R102. doi:10.1186/gb-2011-12-10-r102. PMC . PMID 22014239.
- Schultes, R. E., A. Hofmann, and C. Rätsch. 2001. The nectar of delight. In: Plants of the Gods 2nd ed., Healing Arts Press, Rochester, Vermont, pp. 92–101. ISBN 0-89281-979-0
- Song, B.-H.; Wang, X.-Q.; Li, F.-Z.; Hong, D.-Y. (2001). "Further evidence for paraphyly of the Celtidaceae from the chloroplast gene mat K". Plant Systematics and Evolution. 228: 107–15. doi:10.1007/s006060170041.
- Sytsma, K. J.; Morawetz, J.; Pires, J. C.; Nepokroeff, M.; Conti, E.; Zjhra, M.; Hall, J. C.; Chase, M. W. (2002). "Urticalean rosids: Circumscription, rosid ancestry, and phylogenetics based on rbcL, trnL-F, and ndhF sequences". American Journal of Botany. 89 (9): 1531–46. doi:10.3732/ajb.89.9.1531. PMID 21665755.
- Small, E (1975). "American law and the species problem in Cannabis: Science and semantics". Bulletin on narcotics. 27 (3): 1–20. PMID 1041693.
- "What chemicals are in marijuana and its byproducts?". ProCon.org. 2009. Retrieved 13 January 2013.
- El-Alfy, Abir T.; Ivey, Kelly; Robinson, Keisha; Ahmed, Safwat; Radwan, Mohamed; Slade, Desmond; Khan, Ikhlas; Elsohly, Mahmoud; Ross, Samir (2010). "Antidepressant-like effect of Δ9-tetrahydrocannabinol and other cannabinoids isolated from Cannabis sativa L". Pharmacology Biochemistry and Behavior. 95 (4): 573–82. doi:10.1016/j.pbb.2010.03.004. PMC . PMID 20332000.
- Ahrens J, Demir R, Leuwer M, et al. (2009). "The nonpsychotropic cannabinoid cannabidiol modulates and directly activates alpha-1 and alpha-1-Beta glycine receptor function". Pharmacology. 83 (4): 217–222. doi:10.1159/000201556. PMID 19204413. Retrieved 4 August 2009.
- Small, E; Beckstead, HD (1973). "Common cannabinoid phenotypes in 350 stocks of Cannabis". Lloydia. 36 (2): 144–65. PMID 4744553.
- De Meijer, EP; Bagatta, M; Carboni, A; Crucitti, P; Moliterni, VM; Ranalli, P; Mandolino, G (2003). "The inheritance of chemical phenotype in Cannabis sativa L". Genetics. 163 (1): 335–46. PMC . PMID 12586720.
- Hillig, K. W.; Mahlberg, P. G. (2004). "A chemotaxonomic analysis of cannabinoid variation in Cannabis (Cannabaceae)". American Journal of Botany. 91 (6): 966–75. doi:10.3732/ajb.91.6.966. PMID 21653452.
- Small, E. 1979. Fundamental aspects of the species problem in biology. In: The Species Problem in Cannabis, vol. 1: Science. Corpus Information Services, Toronto, Canada, pp. 5–63. ISBN 0-919217-11-7
- Rieger, R., A. Michaelis, and M. M. Green. 1991. Glossary of Genetics, 5th ed. Springer-Verlag, pp. 458–459. ISBN 0-387-52054-6
- Hillig, Karl W. (2005). "Genetic evidence for speciation in Cannabis (Cannabaceae)". Genetic Resources and Crop Evolution. 52 (2): 161–80. doi:10.1007/s10722-003-4452-y.
- Small, E (1975). "On toadstool soup and legal species of marihuana". Plant Science Bulletin. 21 (3): 34–9.
- Emboden, William A. (1981). "The Genus Cannabis and the Correct Use of Taxonomic Categories". Journal of Psychoactive Drugs. 13 (1): 15–21. doi:10.1080/02791072.1981.10471446. PMID 7024491.
- Schultes, R. E., and A. Hofmann. 1980. Botany and Chemistry of Hallucinogens. C. C. Thomas, Springfield, Illinois, pp. 82–116. ISBN 0-398-03863-5
- Ernest Abel, Marijuana, The First 12,000 years (Plenum Press, New York 1980)
- Butrica James L (2002). "The Medical Use of Cannabis Among the Greeks and Romans". Journal of Cannabis Therapeutics. 2 (2): 51–70. doi:10.1300/j175v02n02_04.
- Herodotus (translated by George Rawlinson) (1994–2009). "The History of Herodotus". The Internet Classics Archive. Daniel C. Stevenson, Web Atomics. Retrieved 13 August 2014.
- "Cannabis: History". deamuseum.org.
- Chris Conrad, HEMP, Lifeline to the Future (ISBN 0-9639754-1-2)
- Jack Herer, The Emperor Wears No Clothes (ISBN 1-878125-00-1)
- Peter Stratford, Psychedelics Encyclopaedia (ISBN 0-914171-51-8)
- Linnaeus, C. 1753. Species Plantarum 2: 1027. Salvius, Stockholm. [Facsimile edition, 1957–1959. Ray Society, London, U.K.]
- de Lamarck, J.B. 1785. Encyclopédie Méthodique de Botanique, vol. 1, pt. 2. Paris, France, pp. 694–695
- Small, Ernest; Cronquist, Arthur (1976). "A Practical and Natural Taxonomy for Cannabis". Taxon. 25 (4): 405–35. doi:10.2307/1220524. JSTOR 1220524.
- Winek, Charles L. (1977). "Some Historical Aspects of Marijuana". Clinical Toxicology. 10 (2): 243–53. doi:10.3109/15563657708987969. PMID 322936.
- Serebriakova T. Ya. and I. A. Sizov. 1940. Cannabinaceae Lindl. In: Vavilov N. I. (ed.), Kulturnaya Flora SSSR, vol. 5, Moscow-Leningrad, USSR, pp. 1–53. [in Russian]
- Watts, G. (2006). "Cannabis confusions". BMJ. 332 (7534): 175–6. doi:10.1136/bmj.332.7534.175. PMC . PMID 16424501.
- Ernest Small (biography). National Research Council Canada. Retrieved on 23 February 2007
- Small, Ernest; Jui, Perry Y.; Lefkovitch, L. P. (1976). "A Numerical Taxonomic Analysis of Cannabis with Special Reference to Species Delimitation". Systematic Botany. 1 (1): 67–84. doi:10.2307/2418840. JSTOR 2418840.
- Schultes R. E.; Klein W. M.; Plowman T.; Lockwood T. E. (1974). "Cannabis: an example of taxonomic neglect". Harvard University Botanical Museum Leaflets. 23: 337–367.
- Anderson, L. C. 1974. A study of systematic wood anatomy in Cannabis. Harvard University Botanical Museum Leaflets 24: 29–36. Retrieved on 23 February 2007
- Anderson, L. C. 1980. Leaf variation among Cannabis species from a controlled garden. Harvard University Botanical Museum Leaflets 28: 61–69. Retrieved on 23 February 2007
- Emboden, William A. (1974). "Cannabis — a polytypic genus". Economic Botany. 28 (3): 304–310. doi:10.1007/BF02861427.
- Schultes, R. E. 1970. Random thoughts and queries on the botany of Cannabis. In: Joyce, C. R. B. and Curry, S. H. (eds), The Botany and Chemistry of Cannabis. J. & A. Churchill, London, pp. 11–38.
- Interview with Robert Connell Clarke. 1 January 2005. NORML, New Zealand. Retrieved on 19 February 2007
- Mandolino, G.; Carboni, A.; Forapani, S.; Faeti, V.; Ranalli, P. (1999). "Identification of DNA markers linked to the male sex in dioecious hemp (Cannabis sativa L.)". TAG Theoretical and Applied Genetics. 98: 86–92. doi:10.1007/s001220051043.
- Forapani, Silvia; Carboni, Andrea; Paoletti, Claudia; Moliterni, V. M. Cristiana; Ranalli, Paolo; Mandolino, Giuseppe (2001). "Comparison of Hemp Varieties Using Random Amplified Polymorphic DNA Markers". Crop Science. 41 (6): 1682. doi:10.2135/cropsci2001.1682.
- Mandolino, Giuseppe; Ranalli, Paolo (2002). "The Applications of Molecular Markers in Genetics and Breeding of Hemp". Journal of Industrial Hemp. 7: 7–23. doi:10.1300/J237v07n01_03.
- Gilmore, Simon; Peakall, Rod; Robertson, James (2003). "Short tandem repeat (STR) DNA markers are hypervariable and informative in Cannabis sativa: Implications for forensic investigations". Forensic Science International. 131 (1): 65–74. doi:10.1016/S0379-0738(02)00397-3. PMID 12505473.
- Kojoma, Mareshige; Iida, Osamu; Makino, Yukiko; Sekita, Setsuko; Satake, Motoyoshi (2002). "DNA Fingerprinting of Cannabis sativa Using Inter-Simple Sequence Repeat (ISSR) Amplification". Planta Medica. 68 (1): 60–3. doi:10.1055/s-2002-19875. PMID 11842329.
- Dr. Paul G. Mahlberg's Cannabis Research. North American Industrial Hemp Council. Retrieved on 23 February 2007
- Hillig, Karl William. 2005. A systematic investigation of Cannabis. Doctoral Dissertation. Department of Biology, Indiana University. Bloomington, Indiana. Published by UMI. Retrieved on 23 February 2007 Archived 21 November 2008 at the Wayback Machine.
- Hillig, Karl W (2004). "A chemotaxonomic analysis of terpenoid variation in Cannabis". Biochemical Systematics and Ecology. 32 (10): 875–891. doi:10.1016/j.bse.2004.04.004.
- 2005. Rasta lends its name to a third type of Cannabis. New Scientist 2517: 12. Retrieved on 24 February 2007
- Gilmore, Simon; Peakall, Rod; Robertson, James (2007). "Organelle DNA haplotypes reflect crop-use characteristics and geographic origins of Cannabis sativa". Forensic Science International. 172 (2–3): 179–90. doi:10.1016/j.forsciint.2006.10.025. PMID 17293071.
- "Drug Toxicity". Web.cgu.edu. Retrieved 17 February 2011.
- "Introduction". NORML. Retrieved 17 February 2011.
- Cannabis. "Erowid Cannabis (Marijuana) Vault : Effects". Erowid.org. Retrieved 17 February 2011.
- Block, R (1998). "Sedative, Stimulant, and Other Subjective Effects of Marijuana: Relationships to Smoking Techniques". Pharmacology Biochemistry and Behavior. 59 (2): 405–412. doi:10.1016/S0091-3057(97)00453-X.
- Zuardi, A. W.; Shirakawa, I.; Finkelfarb, E.; Karniol, I. G. (1982). "Action of cannabidiol on the anxiety and other effects produced by ?9-THC in normal subjects". Psychopharmacology. 76 (3): 245–50. doi:10.1007/BF00432554. PMID 6285406.
- Fusar-Poli, Paolo; Crippa, José A.; Bhattacharyya, Sagnik; Borgwardt, Stefan J.; Allen, Paul; Martin-Santos, Rocio; Seal, Marc; Surguladze, Simon A.; O'Carrol, Colin; Atakan, Zerrin; Zuardi, Antonio W.; McGuire, Philip K. (2009). "Distinct Effects of Δ9-Tetrahydrocannabinol and Cannabidiol on Neural Activation During Emotional Processing". Archives of General Psychiatry. 66 (1): 95–105. doi:10.1001/archgenpsychiatry.2008.519. PMID 19124693.
- Nutt, David; King, Leslie A; Saulsbury, William; Blakemore, Colin (2007). "Development of a rational scale to assess the harm of drugs of potential misuse". The Lancet. 369 (9566): 1047–53. doi:10.1016/S0140-6736(07)60464-4. PMID 17382831.
- "Marijuana Detection Times Influenced By Stress, Dieting". NORML. Retrieved 17 February 2011.
- "Cannabis use and panic disorder". Cannabis.net. Retrieved 17 February 2011.
- "Myths and Facts About Marijuana". Drugpolicy.org. Retrieved 17 February 2011.
- Borgelt LM, Franson KL, Nussbaum AM, Wang GS (February 2013). "The pharmacologic and clinical effects of medical cannabis". Pharmacotherapy (Review). 33 (2): 195–209. doi:10.1002/phar.1187. PMID 23386598.
- Whiting, PF; Wolff, RF; Deshpande, S; Di Nisio, M; Duffy, S; Hernandez, AV; Keurentjes, JC; Lang, S; Misso, K; Ryder, S; Schmidlkofer, S; Westwood, M; Kleijnen, J (23 June 2015). "Cannabinoids for Medical Use: A Systematic Review and Meta-analysis.". JAMA. 313 (24): 2456–2473. doi:10.1001/jama.2015.6358. PMID 26103030.
- Wang, T.; Collet, J.-P.; Shapiro, S.; Ware, M. A. (2008). "Adverse effects of medical cannabinoids: A systematic review". Canadian Medical Association Journal. 178 (13): 1669–78. doi:10.1503/cmaj.071178. PMC . PMID 18559804.
- England, TJ; Hind, WH; Rasid, NA; O'Sullivan, SE (March 2015). "Cannabinoids in experimental stroke: a systematic review and meta-analysis". Journal of Cerebral Blood Flow and Metabolism. 35 (3): 348–58. doi:10.1038/jcbfm.2014.218. PMID 25492113.
- Butticè, Claudio (December 9, 2015). "Therapeutic Cannabis for children – a possible new treatment for epilepsy". Meds News. Retrieved February 2, 2016.
- "Hemp Facts". Naihc.org. Retrieved 17 February 2011.
- "The cultivation and use of hemp in ancient China". Hempfood.com. Retrieved 17 February 2011.
- Van Roekel; Gerjan J. (1994). "Hemp Pulp and Paper Production". Journal of the International Hemp Association. Wageningen, The Netherlands.
- Atkinson, Gail (2011). "Industrial Hemp Production in Alberta". CA: Government of Alberta, Agriculture and Rural Development.
- Ben Amar M (2006). "Cannabinoids in medicine: a review of their therapeutic potential" (PDF). Journal of Ethnopharmacology (Review). 105 (1–2): 1–25. doi:10.1016/j.jep.2006.02.001. PMID 16540272.
- Hulsewé (1979), p. 183.
- Russo, E. B.; Jiang, H.-E.; Li, X.; Sutton, A.; Carboni, A.; Del Bianco, F.; Mandolino, G.; Potter, D. J.; Zhao, Y.-X.; Bera, S.; Zhang, Y.-B.; Lü, E.-G.; Ferguson, D. K.; Hueber, F.; Zhao, L.-C.; Liu, C.-J.; Wang, Y.-F.; Li, C.-S. (2008). "Phytochemical and genetic analyses of ancient cannabis from Central Asia". Journal of Experimental Botany. 59 (15): 4171–82. doi:10.1093/jxb/ern260. PMC . PMID 19036842.
- Mallory and Mair (2000), p. 262.
- Mallory and Mair (2000), p. 306.
- Abel, Ernest L. (1980). "Marijuana – The First Twelve Thousand Years". Chapter 1: Cannabis in the Ancient World. India: The First Marijuana-Oriented Culture.
- Pilcher, Tim (2005). Spliffs 3: The Last Word in Cannabis Culture?. Collins & Brown Publishers. p. 34. ISBN 1-84340-310-2. ISBN 978-1-84340-310-4.
- Vindheim, Jan Bojer. "The History of Hemp in Norway". The Journal of Industrial Hemp. International Hemp Association.
- Kaplan, Aryeh (1981). The Living Torah. New York. p. 442. ISBN 0-940118-35-1.
- Ernest, Abel (1979). A Comprehensive Guide to Cannabis Literature. Greenwood Press. p. 14. ISBN 978-0-313-20721-1.
- Joseph Owens (1982). Dread, The Rastafarians of Jamaica. London: Heinemann. ISBN 0-435-98650-3.
- The Ethiopian Zion Coptic Church. "Marijuana and the Bible". Schaffer Library of Drug Policy. Retrieved 13 September 2007.
- "Zion Light Ministry". Retrieved 20 August 2007.
- Chris Bennett, Lynn; Osburn, Judy Osburn (1938). Green Gold: the Tree of LifeMarijuana in Magic & Religion. Access Unlimited. p. 418. ISBN 0-9629872-2-0.
- "The Hawai'i Cannabis Ministry". Retrieved 13 September 2007.
- "Cantheism". Retrieved 13 September 2007.
- "Cannabis Assembly". Retrieved 13 September 2007.
- Ainsworth, C (2000). "Boys and Girls Come Out to Play: The Molecular Biology of Dioecious Plants". Annals of Botany. 86 (2): 211–221. doi:10.1006/anbo.2000.1201.
- de Meijer, E. P. M. 1999. Cannabis germplasm resources. In: Ranalli P. (ed.). Advances in Hemp Research, Haworth Press, Binghamton, NY, pp. 131–151. ISBN 1-56022-872-5
- "Cannabis as a licit crop: recent developments in Europe". Retrieved February 2008. Check date values in:
- Schumann, Erika; Peil, Andreas; Weber, Wilhelm Eberhard (1999). Genetic Resources and Crop Evolution. 46 (4): 399–407. doi:10.1023/A:1008696018533. Missing or empty
- Ranalli, Paolo (2004). "Current status and future scenarios of hemp breeding". Euphytica. 140: 121–131. doi:10.1007/s10681-004-4760-0.
- Hirata K (1924). "Sex reversal in hemp". Journal of the Society of Agriculture and Forestry. 16: 145–168.
- Schaffner, John H. (1931). "The Fluctuation Curve of Sex Reversal in Staminate Hemp Plants Induced by Photoperiodicity". American Journal of Botany. 18 (6): 424–30. doi:10.2307/2435878. JSTOR 2435878.
- Truţa, E; Gille, E; Tóth, E; Maniu, M (2002). "Biochemical differences in Cannabis sativa L. Depending on sexual phenotype". Journal of applied genetics. 43 (4): 451–62. PMID 12441630.
- Bridges, Calvin B. (1925). "Sex in Relation to Chromosomes and Genes". The American Naturalist. 59 (661): 127–37. doi:10.1086/280023. JSTOR 2456354.
- Schaffner, John H. (1929). "Heredity and sex". Ohio Journal of Science. 29 (1): 289–300. hdl:1811/2398.
- Negrutiu, I; Vyskot, B; Barbacar, N; Georgiev, S; Moneger, F (2001). "Dioecious plants. A key to the early events of sex chromosome evolution". Plant Physiology. 127 (4): 1418–24. doi:10.1104/pp.010711. PMC . PMID 11743084.
- Menzel, Margaret Y. (1964). "Meiotic Chromosomes of Monoecious Kentucky Hemp (Cannabis sativa)". Bulletin of the Torrey Botanical Club. 91 (3): 193–205. doi:10.2307/2483524. JSTOR 2483524.
- Hong, Shao; Clarke, Robert C. (1996). "Taxonomic studies of Cannabis in China". Journal of the International Hemp Association. 3 (2): 55–60.
- Peil, A; Flachowsky, H; Schumann, E; Weber, WE (2003). "Sex-linked AFLP markers indicate a pseudoautosomal region in hemp (Cannabis sativa L.)". Theoretical and Applied Genetics. 107 (1): 102–9. doi:10.1007/s00122-003-1212-5 (inactive 2016-08-19). PMID 12835935.
- Sakamoto, K; Shimomura, K; Komeda, Y; Kamada, H; Satoh, S (1995). "A male-associated DNA sequence in a dioecious plant, Cannabis sativa L". Plant & cell physiology. 36 (8): 1549–54. PMID 8589931.
- Sakamoto, Koichi; Abe, Tomoko; Matsuyama, Tomoki; Yoshida, Shigeo; Ohmido, Nobuko; Fukui, Kiichi; Satoh, Shinobu (2005). "RAPD markers encoding retrotransposable elements are linked to the male sex inCannabis sativaL". Genome. 48 (5): 931–6. doi:10.1139/g05-056. PMID 16391699.
- Törjék, Ottó; Bucherna, Nándor; Kiss, Erzsébet; Homoki, Hajnalka; Finta-Korpelová, Zsuzsanna; Bócsa, Iván; Nagy, István; Heszky, László E. (2002). Euphytica. 127 (2): 209–218. doi:10.1023/A:1020204729122. Missing or empty
- Tanurdzic, M.; Banks, JA (2004). "Sex-Determining Mechanisms in Land Plants". The Plant Cell Online. 16 (Suppl): S61–71. doi:10.1105/tpc.016667. PMC . PMID 15084718.
- Mohan Ram, HY; Sett, R (1982). "Induction of fertile male flowers in genetically female Cannabis sativa plants by silver nitrate and silver thiosulphate anionic complex". Theoretical and Applied Genetics. 62 (4): 369–75. doi:10.1007/BF00275107 (inactive 2016-08-19). PMID 24270659.
- Shao, Hong; Song, Shu-Juan; Clarke, Robert C. (2003). "Female-Associated DNA Polymorphisms of Hemp (Cannabis sativaL.)". Journal of Industrial Hemp. 8: 5–9. doi:10.1300/J237v08n01_02.
- "cannabis" OED Online. July 2009. Oxford University Press. 2009. 
- "Online Etymology Dictionary". Etymonline.com. Retrieved 17 February 2011.
- "Judaism and the Legalization of Marijuana?". Algemeiner.com.
- "Is there a place in religious life for marijuana? Ask Yoseph Needelman – Religion". Jewish Journal.
- Reinhard K. Sprenger (2004). Die Entscheidung liegt bei dir!: Wege aus der alltäglichen Unzufriedenheit. Campus Verlag. p. 305. ISBN 3-593-37442-0.
- Rubin, Vera D. (1975). Cannabis and culture. The Hague: Mouton. p. 305. ISBN 90-279-7669-4.
- Black, Jeremy; George, Andrew; Nicholas, Postgate, eds. (1999). A Concise Dictionary of Akkadian. SANTAG. 5 (2 ed.). Wiesbaden: Harrassowitz Verlag. ISBN 9783447042642.
- Deitch, Robert (2003). Hemp: American History Revisited: The Plant with a Divided History. Algora Pub. ISBN 0-87586-206-3.
- Earleywine, Mitchell (2005). Understanding Marijuana: A New Look at the Scientific Evidence. Oxford University Press. ISBN 0-19-513893-7.
- Emmett, David; Graeme Nice (2009). What you need to know about cannabis: understanding the facts. Jessica Kingsley Publishers. ISBN 1-84310-697-3.
- Hulsewé, A. F. P. (1979). China in Central Asia: The Early Stage 125 BC – AD 23: an annotated translation of chapters 61 and 96 of the History of the Former Han Dynasty. E. J. Brill, Leiden. ISBN 90-04-05884-2.
- Geoffrey William, Guy; Brian Anthony Whittle; Philip Robson (2004). The medicinal uses of cannabis and cannabinoids. Pharmaceutical Press. ISBN 0-85369-517-2.
- Holland, Julie M.D. (2010). The Pot Book: A Complete Guide to Cannabis: Its Role in Medicine, Politics, science, and culture. Park Street Press. ISBN 978-1-59477-368-6.
- Iversen, Leslie L (2008). The science of marijuana (2nd ed.). Oxford University Press. ISBN 978-0-19-532824-0.
- Jenkins, Richard (2006). Cannabis and Young People: Reviewing the Evidence. Jessica Kingsley. ISBN 1-84310-398-2.
- Lambert, Didier M (2008). Cannabinoids in Nature and Medicine. Wiley-VCH. ISBN 3-906390-56-X.
- Mallory, J. P. and Victor H. Mair (2000). The Tarim Mummies: Ancient China and the Mystery of the Earliest Peoples from the West. Thames & Hudson, London. ISBN 0-500-05101-1.
- Roffman, Roger A; Robert S. Stephens (2006). Cannabis Dependence: Its Nature, Consequences, and Treatment. Cambridge University Press. ISBN 0-521-81447-2.
- Russo, Ethan; Melanie Creagan Dreher; Mary Lynn Mathre (2004). Women and Cannabis: Medicine, Science, and Sociology. Haworth Press. ISBN 0-7890-2101-3.
- Solowij, Nadia (1998). Cannabis and Cognitive Functioning. Cambridge University Press. ISBN 0-521-59114-7.
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