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Scientific classification
Kingdom: Plantae
Division: Magnoliophyta
Class: Magnoliopsida
Order: Rosales
Family: Cannabaceae
Genus: Cannabis
Cannabis is a genus of dioecious, annual herbs belonging to the family Cannabaceae, which was formerly placed with the nettles in the order Urticales, but is now in the order Rosales. There is phylogenetic controversy as to whether the cultivated varieties of the plant are of a single species (Cannabis sativa) or represent distinct species (such as those called Cannabis indica, Cannabis ruderalis, or Cannabis americana).

Varieties of the plant grow in most climates. The tough fiber of the plant is known as hemp and has numerous textile uses. Its seeds, used in bird feed, are a valuable source of protein, energy, and long-chain fatty acids. Containing mildly hallucinogenic and other psychoactive and physiologically active chemicals known as cannabinoids, the buds and leaves of the plant are used recreationally and medicinally; such a preparation is often referred to as marijuana (archaic: marihuana; see street names below) and, today, is usually consumed orally or by inhalation in smoking or vaporization.

Concentrated preparations derived from THC-laden resin secreted from the plant are known as hashish. Historically, tinctures, teas, and ointments were also common preparations, especially medicinally.

Table of contents
1 Plant Physiology
2 THC Content
3 Effects of Human Consumption
4 Medical use
5 Preparations for human consumption
6 Common Slang
7 History
8 Related articles
9 External links

Plant Physiology

Cannabis reproduces sexually. The female plant forms buds which can produce hundreds of seeds. Males reach sexual maturity several weeks prior to females. Although a gene disposes a plant to become male, environmental factors, including the diurnal light cycle, can alter the sex. Natural hermaphrodites, with both male and female parts, are usually sterile but artificially induced hermaphrodites can have fully functional reproductive organs. 'Feminized' seed sold by many commercial seed suppliers are derived from artificially hermaphodytic females that lack the male gene or by treating the seeds with hormones.

Cannabis uses C4 photosynthesis, so is not dependent upon a night cycle for carbon dioxide absorption. A cannabis plant in the vegetative growth phase of its life cycle can thrive under twenty-four hour daylight conditions, although some growers advocate a small rest period to avoid overstressing the plant. Flowering usually occurs when darkness exceeds eleven hours per day and can take up to six weeks.

In soil, the optimum pH for the plant is 5.8 to 6.5. In hydroponic growing, the nutrient solution is best at 5.5 to 6.1, making cannabis well-suited to hydroponics because most bacteria and fungii have difficulty growing in this pH range.

THC Content

The main psychoactive substance in cannabis is Δ-9-tetrahydrocannabinol (also known as D-9-THC or THC), but the plant contains about 60 cannabinoids in total, including two others of particularly high concentration, cannabinol (CBN) and cannabidiol (CBD). Differences in the chemical composition of cannabis varieties can produce very different human reactions, and the complexity of the composition of the plant is one reason why its effects can differ from that of the synthetic version of THC, dronabinol.

Although the potency of most cannabis varieties is uncertain, most cannabis contains below 8% THC. Selective breeding and modern cultivation techniques, such as hydroponics have produced varieties of up to 25% THC content. With varieties containing below 2-3% THC, such as those specifically cultivated for usage as hemp, smoking produces lightheadedness or mild headache. The THC content is also affected by the sex of the plant, with female plants generating more resin than their male counterparts. Seedless varieties derived from unpollinated female plants, with high THC content, are sometimes described as sinsemilla (Spanish: "without seed"), or under a catch-all term as "skunk."

High relative concentrations of these chemicals significantly modifies the effects of the plant. THC is associated with an energetic, cerebral high, while CBD is associated with a relaxed, more drowsy high. CBN is not fully understood at this point, but high concentrations usually have hallucinogenic effects.

Because THC breaks down into CBD and other cannabinoids as buds mature, the time of harvest can significantly modify the effects of the plant. Because many commercial process growers often wait until the buds fully mature to ensure maximum weight, low-grade cannabis is usually high in CBD with relatively low THC content.

Effects of Human Consumption

Acute effects of marijuana consumption vary greatly by individual and by the qualities of particular varieties, but for the general population usually include some or all of the following:

Largely mental

Largely physical

The effects of the cannabis plant vary according to the individual, the environment, the variety of plant, and the method of use. Smoking, especially, may pose the greatest risk to physical health. Vaporizing the cannabinoids from the plant is the safest method of consumption. A safe environment among friendly companions is traditionally recommended to first-time users.

THC has an effect on the modulation of the immune system which may have an effect on malignant cells, but there is insufficient scientific study to determine whether this might promote or limit cancer. Cannabinoid receptors are also present in the human reproductive system, but there is insufficient scientific study to conclusively determine the effects of cannabis on reproduction. Mild allergies to cannabis may be possible in some members of the population.

Lethal dose

No fatal overdose due to cannabis use has ever been recorded in humans. According to the Merck Index, 12th edition, the LD50, the lethal dose for 50% of tested rats, was 42 milligrams per kilogram of body weight when inhaled. As for oral consumption, the LD50 for rats was 1270 mg/kg and 730 mg/kg for males and females, respectively. It would be impossible for THC in blood plasma to reach such a level in human cannabis smokers. With other methods of administration, such a level may be feasible, though highly unlikely. Moreover, some evidence suggests that toxic levels may be higher for humans than for rats.

Tolerance and Withdrawal

Although it can be habit-forming, the use of cannabis does not result in physical dependence. Depending on the level of use, tolerance vanishes with a few days of abstinence, and there is no physical withdrawal. There is some evidence that correlates long-term use with depression and aggravation of pre-existing mental conditions. However, the relationship between depression and drug abuse is not fully understood, and heavy drug use may be the result of a mental condition instead of the cause.

Long-term effects on the mind and brain

There is little decisive scientific evidence about long-term psychological, neurological, and cognitive effects of cannabis use. Cannabis' effects on the mind and brain is a subject of great controversy. Many old studies which purported to demonstrate such effects were deeply flawed, with strong bias and poor methodology.

There is a correlation between cannabis use and mental illnesses like psychosis and schizophrenia but there is no evidence of causation, and the physiological effects of cannabis indicate the likelihood of persons with such diseases using cannabis to alleviate such diseases and their symptoms. Also, rather than causing these illnesses, cannabis may trigger latent conditions or be part of a complex coordination of causes. An amotivational syndrome appears in young people who consume cannabis with high frequency and for a long period of time, and may persist for a year.

Some studies indicate that THC is toxic to the brains of rats, but only after administration for a tenth of the life of a rat. Such results have not been replicated in larger animals and in humans would indicate toxicity after many years of nearly daily use. Other studies indicate that THC may be a neuroprotective antioxidant. The relevance of these studies to the human nervous system is unknown.

Cannabis use causes significant medium-term decreases in cognitive performance, but general intelligence and cognition appear to return to normal within a month of abstinence, except in cases of extremely heavy use. However, more subtle changes in cognition may persist, and more scientific study is necessary to decisively determine long-term effects on cognitive performance.

Long-term effects of smoking

More scientific study is necessary to determine the physical effects of smoking cannabis. Because of higher levels of dangerous chemicals, cannabis smoke may be more dangerous than tobacco smoke. In addition, many cannabis smokers inhale the smoke deeper into their lungs than do tobacco smokers. However, the average cannabis user smokes far less than the average tobacco user. Also, cannabis is free of impurities and radioactivity that are present in many tobacco products. In addition, the unique constituent of tobacco, nicotine, is known to be particularly damaging to the body whereas the cannabinoids are rather benign. Research indicates that chronic obstructive pulmonary diseases like emphysema are more likely than fatal diseases like cancer.

Infertility effects of marijuana

Reports since the middle ages have claimed that marijuana "drieth up a man's seed". Modern scientific support of this is some understood in terms of premature activation of the hyperactive swimming mode of spermatazoa. A fair use excerpt from a press release (available from eurekalert.org) explains:

"Men who smoke marijuana frequently have significantly less seminal fluid, a lower total sperm count and their sperm behave abnormally, all of which may affect fertility adversely, a new study in reproductive physiology at the University at Buffalo has shown.

This study is the first to assess marijuana's effects on specific swimming behavior of sperm from marijuana smokers and to compare the results with sperm from men with confirmed fertility. Marijuana contains the cannabinoid drug THC (tetrahydrocannabinol), which is its primary psychoactive chemical, as well as other cannabinoids.

Results of the study were presented today (Oct. 13, 2003) at the annual meeting of the American Society of Reproductive Medicine in San Antonio.

"The bottom line is, the active ingredients in marijuana are doing something to sperm, and the numbers are in the direction toward infertility," said Lani J. Burkman, Ph.D., lead author on the study. Burkman is assistant professor of gynecology/obstetrics and urology and head of the Section on Andrology in the UB School of Medicine and Biomedical Sciences. UB's andrology laboratory also carries out sophisticated diagnosis for infertile couples.

"We don't know exactly what is happening to change sperm functioning," said Burkman, "but we think it is one of two things: THC may be causing improper timing of sperm function by direct stimulation, or it may be bypassing natural inhibition mechanisms. Whatever the cause, the sperm are swimming too fast too early." This aberrant pattern has been connected to infertility in other studies, she noted. "

Medical use

Main article: medical marijuana

Medically, cannabis is most often used as an appetite stimulant and pain reliever for certain terminal illnesses such as cancer and AIDS. Also, it is used to relieve certain neurological illnesses such as epilepsy and bipolar disorder. The medical use of cannabis is controversial; it is rarely prescribed by physicians due to its legal status. See the section on History for information on historic and other medical use.

Preparations for human consumption

Cannabis is prepared for human consumption to several forms:

It is most commonly smoked, and usually in a pipe or the form of a rolled cigarette.

Other methods of smoking include the use of water pipes, or "bongs", and buckets, which cool the smoke and, in the case of bongs, remove some unwanted impurities. Smoke is generally inhaled in a "hit" by opening an aerating hole called a "carb".

Cannabis may also be orally ingested by blending it with alcohol or fats. The effects are significantly reduced if it is not so blended. The effects of ingested cannabis are usually not recognizable for more than thirty minutes (many times longer), making it harder for users to regulate their dosage. Butter preparations are included in foods, commonly cookies and brownies. A drink popular in India, called bhang, includes milk and flavoring herbs (e.g: cloves or cinnamon). See also hashish and hashish oil.

The seeds of the hemp plant are also eaten and roasted, as well as being used to make hemp seed oil. A few restaurants that specialize in food with hemp seeds have opened, and appeal mostly to a countercultural clientele. Hemp seeds contain little THC.

Another method of consumption is vaporization. Vaporization allows the cannabis resins (THC and other cannabinoids) to be extracted into a vapor by heating without burning the plant material. This is advantageous because most of the toxic chemicals found in cannabis and tobacco smoke are byproducts of the combustion process. When cannabis is heated to about 190°C;, its resins are released into an unburnt vapor which can be inhaled.

Common Slang

Cannabis: bud, cheeba, chronic, dagga (from Afrikaans via South Africa), dak, dank, dope, doobage, draw, dro (derived from hydroponics), electric puha (from puha, a plant in New Zealand), frodis (from The Monkees), ganja, grass, green, hash, hay, herb, indo, instaga, IZM, KB (kind bud/killer bud), kind, leaf, Mary Jane, nugget, nug, pot, reefer, schwag (low quality), sensi, skunk, sticky-icky-icky, tea, tree, whacky tobacky, weed.

Cigarette: binge, blunt (cigar papers), bomb, bomber, doobie, fatty, grifo, hooter, J, jacob, joint, L (cigar papers), muggle, reefer, rope, spliff.

Reefer was common in the early twentieth century, but it is now oftenly used only humorously, often in reference to the 1930s propaganda film Reefer Madness, which significantly overstated the effects of cannabis.

Intoxication: baked, blasted, blazed, blitzed, buzzed, chinky eyed (may be offensive), faded, fucked up, gone, high, keyed, lit, lifted, mashed, mullered (UK), ripped, smashed, spaced, spaced out, stoned, throwed, toasted, wasted, zonked, zooted.

To smoke: bake, blaze, burn, chief, light up, sesh (from session), toke (up)

Early twentieth century: mez, muggles, gage, viper jive.

Potent strains: White widow (light green-white in appearance), Buddha, C99, AK-47 (C. sativa/C. indica cross), Bubblegum (very sticky), JuicyFruit, Orange Bud and Blueberry (plant smells or tastes somewhat like its name); G-13 (developed at the University of Washington); BC Bud (from British Columbia, Canada); Thunderfuck, Northern-lights (these two natives of Alaska), purple haze, kush, Thai or Thai stick (the legitimate product is C. sativa from Thailand or US Grown of Thai seed, the buds being long and treelike in appearance, often with string wrapped in a spiral pattern for the purpose of holding the bud together); Maui Wowie (from Hawai'i); Acapulco Gold. The term Thai stick is also used for imitation marijuana.

The meaning of each of these terms may vary by region and context.

It should be noted that, in part due to the illegal status of cannabis in most countries, false information about origin and THC content is perpetuated by dishonest sellers to boost sales or justify high prices.


The use of cannabis, for food, fibers, and medicine, is thought to go back at least five millennia. Neolithic archaeological sites in China include cannabis seeds and plants. The first known mention of cannabis is in a Chinese medical text of 2737 BC. It was used as medicine throughout Asia and the Middle East to treat a variety of conditions. In India particularly, cannabis was associated with Shiva.

Cannabis was well known to the Scythians. Germans grew hemp for its fibers to make nautical ropes and material for clothes since ancient times. Large fields of hemp along the banks of the Rhine are featured in 19th century copper etchings.

The hemp plant has to be soaked to harvest the fiber. This liquid may be drunk; in modern Germany, some bars serve hemp beer and hemp wine, but the hemp used is required by law to contain very minimal levels of THC.

Cannabis was used medicinally in the western world (usually as a tincture) around the middle of the 19th century. It was famously used to treat Queen Victoria's menstrual pains, and was available from shops in the US. By the end of the 19th century its medicinal use began to fall as other drugs such as aspirin took over.

Until 1937, consumption and sale of marijuana was legal in most American states. In some areas it could be openly purchased in bulk from grocers or in cigarette form at newstands, though an increasing number of them had begun to outlaw it. In that year, federal law made possession or transfer of marijuana illegal without the purchase of a by-then incriminating tax stamp throughout the United States (contrary to the advice of the American Medical Association at the time); legal opinions of time held that the federal government could not outlaw it entirely.

The decision of the U.S. Congress was based in part on testimony derived from articles in the newspapers owned by William Randolph Hearst, who was heavily interested in DuPont Inc. Some analysts theorize DuPont wanted to boost declining post-war textile sales, and wished to eliminate hemp fiber as competition. Many argue that this seems unlikely given DuPont's lack of concern with the legal status of cotton, wool, and linen; although it should be noted that hemp's textile potential had not yet been largely exploited, while textile factories already had made large investments in equipment to handle cotton, wool, and linen. Others argue that Dupont wanted to eliminate cannabis because its high natural cellulose content made it a viable alternative to the company's developing innovation: modern plastic. Even more inflammatory and biased were the accusations by that period's US 'drug czar' Henry (Harry) Anslinger. Anslinger charged that the drug provoked murderous rampages in previously solid citizens. Anslinger testified that cannabis "makes darkies feel equal to white men," a complaint typical of much of the anti-drug rhetoric of the time, which for example emphasised opium's role in promoting Anglo-Chinese miscegenation. He told the married men in the audience: "Gentlemen, it will make your wives want to have sex with a Black man!" Anslinger also popularized the word marihuana for the plant, using a Mexican derived word (believed to be derived from a Brazilian Portuguese term for inebriation) in order to associate the plant with increasing numbers of Mexican immigrants, creating a negative stereotype which persists to this day.

Cannabis has a prominent role in the Rastafarian religion.

Although cannabis has been used recreationally throughout its history, it first became well known in the United States during the jazz scene of the late 1920s and 30s. Louis Armstrong became one of its most prominent and life-long devotees. Cannabis use was also a prominent part of 1960s counterculture.

Cannabis is currently the most widely used illegal drug in the world.

Federal Bureau of Narcotics propaganda poster used in the late 1930s and 1940s

Related articles

External links

Drug Information



Note that some of these sites contain misleading statements.

Growing the plant



Note: This article should exchange data with Hemp''.