Cannabis sativa is an annual herbaceous flowering plant indigenous to eastern Asia but now of cosmopolitan distribution due to widespread cultivation. It has been cultivated throughout recorded history, used as a source of industrial fiber, 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.
The flowers of Cannabis sativa are unisexual and plants are most often either male or female. It is a short-day flowering plant, with staminate (male) plants usually taller and less robust than pistillate (female or male) plants. 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. Under typical conditions with a light period of 12 to 14 hours both sexes are produced in equal numbers because of heritable X and Y chromosomes. Although genetic factors dispose a plant to become male or female, environmental factors including the diurnal light cycle can alter sexual expression. 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.
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. 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. Differences in the chemical composition of Cannabis varieties may produce different effects in humans. Synthetic THC, called dronabinol, does not contain cannabidiol (CBD), cannabinol (CBN), or other cannabinoids, which is one reason why its pharmacological effects may differ significantly from those of natural Cannabis preparations.
Cannabis sativa seeds are chiefly used to make hempseed oil which can be used for cooking, lamps, lacquers, or paints. They can also be used as caged-bird feed, as they provide a wonderful source of nutrients for most animals. 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 (called marijuana) 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. Cannabis sativa has been used in medical practices as a therapeutic alternative for people with mental illnesses to lift off stress which leads recreational users to believe that sativa can aid them with their stress heavy lives. However, recent ethnopharmacology studies have shown that sativa can actually cause sleep disorders and heighten neurological and psychiatric illness.