08/08/2017
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Cannabis sativa
Scientific classification
Kingdom:
Plantae
Clade:
Angiosperms
Clade:
Eudicots
Clade:
Rosids
Order:
Rosales
Family:
Cannabaceae
Genus:
Cannabis
Species:
C. sativa
Binomial name
Cannabis sativa
L.
Subspecies
C. sativa ssp. sativa
C. sativa ssp. indica
C. sativa ssp. ruderalis
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Cannabis sativa is an annual herbaceous plant in the Cannabis genus. It is a member of a small, but diverse family of flowering plants of the Cannabaceae family. It has been cultivated throughout recorded history, used as a source of industrial fibre, seed oil, food, recreation, religious and spiritual moods and medicine. Each part of the plant is harvested differently, depending on the purpose of its use. The species was first classified by Carl Linnaeus in 1753.[1]
Contents [hide]
1
Plant physiology
2
Cultivars
3
Pharmacology
4
Chemical constituents
4.1
Difference between C. sativa and C. indica
5
Common uses
6
Cultivation
7
See also
8
References
9
External links
Plant physiology[edit]
Main articles: Cannabis and Cannabis cultivation
The flowers of Cannabis sativa are unisexual and plants are most often either male or female.[2] It is a short-day flowering plant, with staminate (male) plants usually taller and less robust than pistillate (female) plants[3] The flowers of the female plant are arranged in racemes and can produce hundreds of seeds. Male plants shed their pollen and die several weeks prior to seed ripening on the female plants. Although genetic factors dispose a plant to become male or female, environmental factors including the diurnal light cycle can alter sexual expression.[4] Naturally occurring monoecious plants, with both male and female parts, are either sterile or fertile but artificially induced "hermaphrodites" can have fully functional reproductive organs. "Feminized" seed sold by many commercial seed suppliers are derived from artificially "hermaphrodytic" females that lack the male gene, or by treating the plants with hormones or silver thiosulfate.
Cultivars[edit]
Broadly, there are three main cultivar groups of cannabis that are cultivated today:
Cultivars primarily cultivated for their fibre, characterised by long stems and little branching.
Cultivars grown for seed which can be eaten entirely raw or from which h**p oil is extracted.
Cultivars grown for medicinal or recreational purposes. A nominal if not legal distinction is often made between industrial h**p, with concentrations of psychoactive compounds far too low to be useful for that purpose, and ma*****na.
Pharmacology[edit]
Main article: Cannabis (drug)
Δ9-tetrahydrocannabinol (THC)
The flower of a hybrid Cannabis indica plant
Cannabis sativa, scientific drawing from c1900
Although the main psychoactive constituent of Cannabis is tetrahydrocannabinol (THC), the plant is known to contain more than 500 compounds, among them at least 113 cannabinoids; however, most of these "minor" cannabinoids are only produced in trace amounts.[5] Besides THC, another cannabinoid produced in high concentrations by some plants is cannabidiol (CBD), which is not psychoactive but has recently been shown to block the effect of THC in the nervous system.[6] Differences in the chemical composition of Cannabis varieties may produce different effects in humans. Synthetic THC, called dronabinol, does not contain CBD, CBN, or other cannabinoids, which is one reason why its pharmacological effects may differ significantly from those of natural Cannabis preparations.
Chemical constituents[edit]
Beside cannabinoids, Cannabis chemical constituents include about 120 compounds responsible for its characteristic aroma. These are mainly volatile terpenes and sesquiterpenes.
α-Pinene[7]
Myrcene[7]
Linalool[7]
Limonene[7]
Trans-β-ocimene[7]
α-Terpinolene[7]
Trans-caryophyllene[7]
α-Humulene,[7] contributes to the characteristic aroma of Cannabis sativa
Caryophyllene,[7] with which some hashish detection dogs are trained[8]
Difference between C. sativa and C. indica[edit]
Studies indicate that, on average, Cannabis sativa has higher levels of CBD compared to THC than C. indica.[9] However, large variability exists within either species, and there is an increasing discussion whether the existing paradigm of the difference between species adequately represents the variability found within the Cannabis genus.[10][11][12] There are five chemotaxonomic types of Cannabis: one with high levels of THC, one which is more fibrous and has higher levels of CBD, one that is an intermediate between the two, another one with high levels of cannabigerol (CBG), and the last one almost without cannabinoids.[13]
Cannabis strains with relatively high CBD:THC ratios are less likely to induce anxiety than vice versa.[14] This may be due to CBD's antagonistic effects at the cannabinoid receptors, compared to THC's partial agonist effect.[15] CBD is also a 5-HT1A receptor (serotonin) agonist, which may also contribute to an anxiolytic-content effect.[16] The effects of sativa are well known for its cerebral high, while indica is well known for its sedative effects which some prefer for night time use.[16] Both types are used as medical cannabis. Indica plants are normally shorter and stockier than sativas.[17] They have broader, deeply serrated leaves and a compact and dense flower cluster.
Common uses[edit]
Main articles: Industrial and personal uses of Cannabis, Cannabis (drug), and H**p
A sack made from h**p fibre
Cannabis sativa seeds are chiefly used to make h**pseed oil which can be used for cooking, lamps, lacquers or paints. They can also be used as caged-bird feed, as they provide a moderate source of nutrients for most birds. The flowers (and to a lesser extent the leaves, stems, and seeds) contain psychoactive chemical compounds known as cannabinoids that are consumed for recreational, medicinal and spiritual purposes. When so used, preparations of flowers (ma*****na) and leaves and preparations derived from resinous extract (e.g., hashish) are consumed by smoking, vaporising and oral ingestion. Historically, tinctures, teas and ointments have also been common preparations. In traditional medicine of India in particular C. sativa has been used as hallucinogenic, hypnotic, sedative, analgesic and anti-inflammatory agent.[18]
Cultivation[edit]
In the case of production related to recreational use of Cannabis, the process of "cloning" provides the grower with DNA identical female plants eliminating the need of seeds for the growing process.
A Cannabis plant in the vegetative growth phase of its life requires more than 12–13 hours of light per day to stay vegetative. Flowering usually occurs when darkness equals at least 12 hours per day[dubious – discuss]. The flowering cycle can last anywhere between nine and fifteen weeks, depending on the strain and environmental conditions.
In soil, the optimum pH for the plant is 6.3 to 6.8. In hydroponic growing, the nutrient solution is best at 5.2 to 5.8, making Cannabis well-suited to hydroponics because this pH range is hostile to most bacteria and fungi.
