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Cannabis Theory

Dive into the theory of Cannabis with us.  

1.

Introduction

2.

Prehuman & Early History

3.

History of Cannabis

4.

Cannabis Biology

5.

Terroir

6.

Appellations

7.

Terminology

8.

The Modern Industry

Introduction

Cannabis Theory Introduction

Welcome to the Cannabis Theory section of our educational resources, where we aim to provide a comprehensive overview of the history, chemistry, social implications, and cultural significance of landrace cannabis. Our ancestors have used landrace cannabis for generations, for various purposes including medicinal, spiritual, and cultural. Unfortunately, landrace cannabis has been subject to significant social and political controversy, leading to its endangerment and loss of genetic diversity.

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While there has been a growing recognition of the potential therapeutic benefits of cannabis, this growing acceptance often overlooks the importance of preserving the unique genetic diversity of landrace cannabis. As a landrace cannabis preservation group, we strive to promote the conservation of landrace cannabis genetics and cultural heritage for future generations.

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We will explore the chemistry of landrace cannabis, including its different compounds and how they interact with the human body. We will also discuss the social and political implications of cannabis use, including the history of prohibition and the current state of legalization. Additionally, we will delve into the cultural significance of landrace cannabis in different regions around the world and how it has been integrated into different cultural traditions.

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Our hope is to collate information that can serve as a resource for anyone interested in learning more about landrace cannabis and its importance to human history, society, and culture.

The Cannabis Plant

Cannabis Sativa, best known as the source of dank nugs, maybe the most controversial and famous plant in the world. At first glance it may seem innocuous - perhaps beautiful, yet the architectural adaptations of C. Sativa are very complex and ingeniously carry out a number of functions. The variations found in height within Cannabis plants are extreme, depending on the environment and whether it was used for stem fiber or not but typically - they range from one to five metres tall.  Hemp has been known to grow much taller, sometimes up to twelve meters in height and it is often confused with C. Sativa. The main stalk is erect, furrowed (especially when large), with a somewhat woody interior and it may be hollow in the internodes (portions of the stem between bases of the leaf stalks). The species is often referred to as a herb or forb (an herbaceous flowering plant that is not grass-like, i.e., not like grasses, sedges, or rushes), despite the fact that the stem is more or less woody. Herbs and forbs are both classified as plants with little to no woody tissues, so these meanings aren't entirely true.

A comprehensive term

In its broadest meaning, “Cannabis” refers to the cannabis plant, especially its psychoactive chemicals (which are used in a variety of illegal and medical drugs), fiber products (such as textiles, plastics, and hundreds of building materials), edible seed products (which are now used in over a hundred processed foods), and all related considerations. In a nutshell, cannabis refers to all facets of the plant, especially its goods and how they are used. Italicization of scientific names, such as Homo sapiens, is customary among biologists and editors. Cannabis corresponds to the plant's biological name, which is italicized (only one species of this genus is commonly recognized, C. sativa L.). “Cannabis” is a non italicized generic abstraction that is generally used as a noun and adjective, and is generally (and sometimes erroneously) applied to cannabis plants and/or some or all of the intoxicant preparations made from them.

Cannabis “Flowers”?

Both for medicinal and nonmedical uses, “herbal marijuana” is the most commonly used type of cannabis. Herbal weed is clearly made up of C. sativa plant oil, so where does it come from? Low-grade marijuana used to be made up of a mixture of foliage, twigs, “seeds” (technically one-seeded fruits called achenes), and material from the flowering part of the plant, and was often derisively referred to as “ditchweed.” However, this word more narrowly applies to wild growing low-tetrahydrocannabinol [low-THC] weedy plants. Only “sinsemilla” (material from the unfertilized female plant's flowering part) is widely harvested nowadays. Botanists use technical jargon to explain how flowers are placed on branches or branch structures on most plants. The word "inflorescence" refers to a cluster of flowers on a terminal branch, as well as the whole branching system bearing flowers. The branching structures are known as "infructescences" when the flowers are fertilized and produce fruits.

 

Many Cannabis strains have been chosen for their ultimate flowering branches, which have culminated in very congested, short branching structures with a large number of flowers. This is marijuana's "buds," which are highly sought after due to their high THC content. Buds are actually "inflorescences," and are a mixture of flowers and the branching system's ultimate little twigs that subtend the flowers. Buds are meristems (growing points or places where cells divide) of stems or flowers, or embryonic stems, leaves, or flowers that will mature and enlarge over time, according to traditional horticultural terminology. The weed industry has embraced and modified the word "bud" to mean something other than what it initially meant, as it has done with a variety of other generic words. The “flowers” of Cannabis sativa are commonly referred to as marijuana. Herbal marijuana was once referred to as "Cannabis Flos" (literally, "cannabis flowers") in pre-World War II drug literature. A flower is generally characterized as a reproductive structure composed of one or more sepals, petals, stamens, and pistils in technical botany. (There are wider botanical meanings available; this is a limited sense botanical definition.) Female C. sativa flowers are devoid of sepals, stamens, and petals. Since a female flower, as seen in Figure 1.6, is practically devoid of THC, it is scientifically incorrect to define or characterize marijuana as the plant's flowers (which are present). (In a related way, states that identify illegal marijuana as the plant's flowers face legal challenges because the content is abuse-free.)

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Figure 1

Cannabis Sativa L. Botanical Illustration From Franz Eugen Köhler's Medizinal-Pflantzen. Published and copyrighted by Gera-Untermhaus, FE Köhler in 1887 (1883–1914)

fig1.5 Female flower with bract

fig1.6 Female flower

fig1.7 Female fruit cluster

fig1.8 Fruit (Achene) with perigonal bract

fig1.9 Achene, wide (flat) side view

fig1.10 Achene, narrow side view

The primary component of marijuana that adds to the drug potential are the "bracts." A “bract” is a modified or specialized leaf, especially one associated with flowers, according to botany. Bracts are small structures in C. sativa that resemble miniature unifoliolate leaves (i.e. leaves with just one leaflet) and are connected with the flowers. Each female flower is covered in a cup-like manner by a "perigonal bract" (shown in Figure 1.5), which enlarges and becomes heavily covered with tiny secretory glands that contain the majority of the THC produced by the plant. (When the name "perigonal bract" is applied to Cannabis, the words "bracteole" and "perigonium" are often used interchangeably, although they have separate meanings when applied to other plants.) The bracts of sinsemilla marijuana, which is created by preventing pollination of female flowers, are tiny and densely coated with secretory glands.

Pollinated buds, on the other hand, grow into “seeds” (achenes), with a slightly greater perigonal bract and a smaller density of secretory glands. In C. sativa, in addition to the tiny perigonal bracts, the flowering axis produces tiny unifoliolate (one-leaved) leaves that are almost identical to the perigonal bracts, and when one moves down the branch bearing flowers (the axis of the bud), there are increasingly larder leaves.

 

Perigonal bracts and tiny young leaves can be seen in the green material visible in Figure 2. The smallest tiny leaves, including the perigonal bracts, are densely packed with tiny secretory glands, while the bigger leaves within the bud have less glands and thus less THC on a relative basis. The larger leaves within buds are often cut away, as discussed later, in order to increase the THC concentration of the buds. To reinforce the argument made earlier in this paragraph, marijuana (sinsemilla) is not simply “flowers,” though a small proportion, maybe 2%, is made up of female flowers that are almost entirely devoid of THC; rather, it is THC-rich content (bracts, tiny leaves) associated with the flowers. The difference made here is admittedly theoretical, and it is unlikely to affect the common use of marijuana as flowering material. While the stigmas of female flowers are initially devoid of THC, they are sticky, and gland heads rich in THC appear to slip away from the bud but get stuck on the stigmas, resulting in the flowers acquiring appreciable THC secondarily.

Figure 2

Strawberry Kush Closeup by Avery Meeker

Image by Avery Meeker

Sexual Reproduction in Cannabis

We humans are preoccupied with sex, which is also an extremely important topic for cannabis. While some species are hermaphrodites, most animals are divided into males and females (so male and female reproductive cells are formed on separate individuals). Most plants, on the other hand, produce both male and female reproductive elements (pollen and eggs respectively) on the same organism. Cannabis sativa is one of a small number of plants that reproduce in an animal-like manner rather than a plant-like manner. Plants bearing only female flowers or only male flowers make up the majority of populations (Figure 1.a & b). Male plants are called "staminate," after the important male floral organs, stamens, while female plants are called "pistillate," after the essential female floral organs, pistils, which hold the eggs. Male plants die after pollination, while female plants live on after pollination, maturing and shedding seeds before frost kills them. Female plants grown in a greenhouse or in climates without a cold winter can survive for years, though their vigor gradually deteriorates. Because of this possible durability, others have called the plants "annual or seasonal depending on climate," but the genus is obviously an annual. In domesticated plants, sex expression has been remarkably manipulated, mostly to the detriment of males.

 

Femaleness has been increasingly valuable in cannabis plants, though males are now considered the lesser sex. Another intriguing fact is that, unlike other mammals, C. sativa's sexual expression can be altered by a multitude of pressures, and females can also be made to become males and vice versa. Male and female plants are nearly identical during the early growth process of Cannabis sativa, which grows leafy branches in the early part of its seasonal life cycle. The timing of floral induction is one of many ecological characteristics of the plant and a key factor in optimizing the plant's productivity for the different purposes for which it is cultivated. Most populations are induced to bloom by shortening days in the late season.

Cannabis_sativa_Koehler_drawing.jpg

Figure 1

Cannabis Sativa L. Botanical Illustration From Franz Eugen Köhler's Medizinal-Pflantzen. Published and copyrighted by Gera-Untermhaus, FE Köhler in 1887 (1883–1914)

fig1.a Flowering male

fig1.b Fruiting female

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Sexual Reproduction in Cannabis

Cannabis plants are extremely diverse, and this has generated extraordinary widespread misunderstanding concerning the classes or categories deserving recognition, not just by the general public but also among professionals in numerous disciplines. It is no exaggeration to say that both the popular literature (notably as reflected by information on the Web) and the professional literature (particularly scientific publications) present highly confused and confusing interpretations of how variation among cannabis plants is structured and what terminology is appropriate. 

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The root of misunderstanding of variability in Cannabis is that humans, not nature, have generated the most conspicuous differences. It is important for clarity of understanding to appreciate the four principal kinds of plant that are significant to human welfare. These are (1) “wild” weedy plants, (2) plants selected for valuable fiber in the stems, (3) plants selected for edible oil–containing seeds, and (4) plants selected for intoxicating and medicinal drugs. The variation pattern exhibited by domesticated kinds of Cannabis is paralleled by many other examples of how humans have enslaved wild species, domesticating them (changing them genetically) into different utilitarian classes with characteristics uniquely suited to different purposes. Numerous domesticated plants and animals have been so drastically altered by selection that they cannot survive without the assistance of humans. Domesticated kinds of C. sativa, however, are frequently very hardy, and when they escape to the wild, they are often capable of living on their own. Biological classification of exclusively wild plants and animals is based only on natural genetic relationships. However, classification of living things that have been substantially altered by humans is often also based on utilitarian considerations, particularly the ways that they have been genetically modified for particular purposes. The many different kinds of plant in C. sativa can be grouped into four basic categories, the first three of which include cultivated plants that have been selected for one of three economic products:

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  1. Fiber from the main stalk (employed for textiles, cordage, and numerous recent applications). 

  2. Oilseed (oil-rich seed employed for human food, livestock feed, nutritional supplements, industrial oils, and occasionally as a biofuel). 

  3. Psychoactive drugs from the flowering parts (used mostly illicitly for recreation and more recently legally as medicine). 

  4. “Wild” (weedy) plants that have escaped from cultivation and grow independently in nature. 

Figure 3

Marijuana growing in a ditch in Buffalo County, Nebraska; photographed in mid-June.

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Wild Plants

Outside of cultivation, Cannabis sativa is generally observed growing as a weed (Figure 3), the presence of such "wild" plants is the subject of much controversy regarding proper classification. The term "wild" can refer to any plant or animal that reproduces in nature without human intervention. However, the word is used in a variety of specific ways, and it's important to appreciate in which way certain cannabis plants are considered "wild." 

Both wolves and feral dogs are considered "wild," but wolves are the descendants of dogs, while feral dogs are just escapes that are more or less similar to domestic dogs, despite being heavily hybridized. The Australian dingo, on the other hand, is an escaped dog who has adapted to life in the wild. As a result, “wild” can refer to (1) groups that have never been tamed by humans (such as wolves), (2) groups that have escaped and developed characteristics more suited to wild life (such as feral dogs), and (3) groups that have escaped and evolved characteristics more suited to wild existence. Occasionally, one can come across four (4) "wolfdogs," who are wolf-dog hybrids that occasionally share genes.

Classes 2, 3, and 4 claim to be “natural” weed plants, but there do not appear to be any truly wild plants that have not been genetically altered by humans. It suggests that the ancient wild ancestor of C. sativa that lived in pre-Neolithic times (i.e., prior to 10,000 BC) is no longer extant, and the world's so-called wild cannabis plants are possibly heavily interbred with cultivated plants. C. sativa plants that thrive outside of cultivation have adaptations that aren't seen in domesticated plants. The genes that adapt wild plants to the stresses of life in the wild are extremely useful for improving cultivated C. sativa varieties. 

Unfortunately, despite their low potential for use as illegal drugs, there have been decades of passionate, costly, and short-sighted attempts to eliminate wild plants in North America. In the United States, law enforcement officials commonly refer to wild-growing C. sativa as "ditch grass." Since nearly all wild-growing plants in North America lack the ability to produce intoxication, ditch weed has become a generic term for all plants that produce little or no intoxication. The informally used word "pot" is the most common of the myriad of words used to refer to marijuana and marijuana plants.

Image by Maximilian Weisbecker

Figure 4

During the "Age of Sail" (from the sixteenth to the mid-nineteenth century), hemp was crucial for Navy sails and rigging.

Fiber Plants

The name "hemp" is used to refer to C. sativa plants used for fiber as well as the fiber derived from the stalk (i.e., the main stem). (When hemp is cultivated for oilseed, it is referred to as "oilseed hemp" or "hempseed," as discussed below.) Hemp was a staple resource for both civilian and military uses in previous centuries, mostly for textiles and cordage. Hemp products have been used in the shipping industry for centuries (Figure 4). Hemp was once billed as "the new billion dollar crop" (Popular Mechanics 1938), with the assertion that it "can be used to manufacture more than 25,000 products, ranging from dynamite to Cellophane".  Despite this, after WWII, C. sativa fiber production in Western countries almost came to an end. However, there has been a revival in interest in fiber applications in recent decades, mostly for nontraditional uses. At the moment, hemp fiber cultivation for different purposes is limited to small, niche markets. The fiber is also used for fabric, cordage, and paper, but these items are very costly and only cater to a small market. New fiber-based products, on the other hand, have re-energized the hemp industry (Roulac 1997; Bouloc et al. 2013). Both the long exterior fibers (bark, phloem) and the short internal fibers (hurds, wood) are now used in specialty pulp materials and composites. Fiberboard, insulation, pressed fiber products, masonry products (concrete, stucco, mortar, and tiles), carpets, straw-bale building materials, animal bedding, and a wide variety of plastics are all examples of these applications. The automotive industry has been at the forefront of pressed fiber and molded plastic product production. Geotextile goods, such as landscaping cloth, take advantage of the fiber's high rot resistance. Hemp has mainly been used for these new fiber applications in Europe, and subsidies were crucial in developing new hemp-related industries.

Indian Hemp

The term "Indian hemp" has been confusingly used to describe intoxicating Asian drug varieties of C. sativa (so-called C. indica Lamarck of India), jute (Corchorus capsularis L., also known as Bengal hemp, Calcutta hemp, and Madras Hemp; see Ash 1948), and Apocynum cannabinum L. (also known as American hemp and by other names), which was used by North American Indians.

Oilseed Plants

The seeds (technically fruits called "achenes"; Figure 5) of Cannabis sativa are used to produce a multipurpose fixed (i.e., nonvolatile) vegetable oil. C. sativa seeds have been an essential source of edible oil in recent decades. The seeds have been referred to as "hempseed" in the past, and this term has now been applied to C. sativa varieties grown specifically for the oilseed. While the use of oilseeds was historically minor compared to fiber applications, commercial hempseed products have much greater importance and promise today than fiber applications. C. sativa seeds are being more commonly accepted as a legal source of medicinals, nutraceuticals (nutritional extractives), and usable (nutritionally fortified) foods. Although “medical marijuana” is generally believed to have amazing therapeutic potential (with good reason), “medical hempseed” also has impressive therapeutic potential.

Figure 5

Cannabis Sativa Achenes

Hemp-Seed-Benefits.jpg

Oilseed Plants

The seeds (technically fruits called "achenes"; Figure 5) of Cannabis sativa are used to produce a multipurpose fixed (i.e., nonvolatile) vegetable oil. C. sativa seeds have been an essential source of edible oil in recent decades. The seeds have been referred to as "hempseed" in the past, and this term has now been applied to C. sativa varieties grown specifically for the oilseed. While the use of oilseeds was historically minor compared to fiber applications, commercial hempseed products have much greater importance and promise today than fiber applications. C. sativa seeds are being more commonly accepted as a legal source of medicinals, nutraceuticals (nutritional extractives), and usable (nutritionally fortified) foods. Although “medical marijuana” is generally believed to have amazing therapeutic potential (with good reason), “medical hempseed” also has impressive therapeutic potential.

Intoxicating Drug Plants

Especially over the last thousand years in Asia, where intoxicating drug preparations (such as marijuana and hashish) have been ingested for ritualistic, religious, and hedonistic purposes, forms of C. sativa with significant concentrations of intoxicating chemicals were chosen. Marijuana use has risen dramatically over the past century, to the point that it is now the world's most common illicit recreational drug. Because of the huge demand for Cannabis, the chemistry and variation patterns of cannabinoids (particularly the key intoxicant THC) have changed drastically. We'll take a better look at this at a later stage.

Figure 6

Patterns of gene flow, genetic stabilization, and genetic destabilization among wild and domesticated races of Cannabis sativa.

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  1. Humans cultivate selections, principally for stem fiber, oilseed, and narcotic floral resin.

  2. Such selections retain their desirable characteristics only if maintained by stabilizing selection (shown here for simplicity only for the oilseed form).

  3. In recent times, deliberate hybridization among oilseed and fiber kinds has generated valuable new selections.

  4. In the absence of stabilizing selection, cultivated plants are likely to undergo populational genetic changes over several generations, that are undesirable agriculturally (degenerative) since the highly selected characters of interest to humans are usually deleterious to the plants (for simplicity, such degeneration is shown only for the oilseed form).

  5. Genes from cultivated plants may be released to the uncultivated gene pool. Selections may escape directly from cultivation and re-establish populations outside of cultivation, or pollen from cultivated selections may fertilize wild plants (for simplicity, such gene escape is shown only for the oilseed form).

  6. Pollen from uncultivated plants may fertilize a cultivated selection, reducing the desired characteristics of the latter (for simplicity, this is shown only for the oilseed form). (7) Pollen from cultivated plants with undesirable characteristics (e.g., from clandestine marijuana plants) may pollinate a cultivated selection (e.g., grown for fiber or oilseed), reducing the desired characteristics of the latter

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From: Evolution and Classification of Cannabis sativa (Marijuana, Hemp) in Relation to Human Utilization, Ernest Small - The Botanical Review

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The Suppression of Cannabis

Cannabis sativa is known for being the most commonly used illegal plant on the planet. Cannabis has been considered a leading drug of trafficking since the Second World War, and nearly all science and industrial development—both drug and nondrug aspects—have been ignored for the majority of the twentieth century. Following WWII, C. sativa became the most commonly illegally grown black market crop in the Western world, with law enforcement putting forth considerable effort to eliminate the plants everywhere they were found. In Western nations, the majority of experimental investigations were either forensic experiments to assist law enforcement or medical and social science aimed at documenting and reducing adverse impacts. Cannabis criminalization has been linked to high drug enforcement costs and social upheaval. Many people have died as a result of the decades-long "war on drugs" waged with extraordinary ferocity against marijuana. Science has been one of the most significant casualties. For much of the past century, the stigma applied to "narcotics" was so serious that scholars endangered their lives by trying to do research on almost every type of cannabis other than its harmfulness. It is fitting to remember the martyrdom of the illustrious Russian crop geneticist N.I. Vavilov (1887–1943), who carried out experimental experiments on C. sativa and amassed invaluable seed collections. Attempting to present scientific reality to a tyrant (Joseph Stalin) resulted in his incarceration and eventual death. It is not unreasonable for elected legislatures of democracies to curb or even forbid taxpayer-funded scientific research. Prohibition of study that bears on ethical problems is more contentious, but at least debatable (such as human reproduction). The quest for evidence that undermines ignorant dogma must not be discouraged, as the sorry past of cannabis shows.

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One of the unfortunate but less apparent effects of cannabis criminalization has been the hasty removal of C. sativa seed collections collected by agriculture departments (mostly in North America) and orders to refuse further collection. Seed banks are stocks of seeds, mainly of crop plants, that have a value far exceeding that of traditional banks' monetary holdings. The conservation of C. sativa's "germplasm capital" is of the utmost importance for the world's future health, just as it is for other important crops such as wheat, barley, rice, and potato.

The Re-Legitimisation of Cannabis

Several advances led to a boom in scientific and industrial growth of C. sativa by the last decade of the twentieth century. First, following a half-century of prohibition, several nations (with the notable exception of the United States) have resurrected the cultivation of the herb for non-drug purposes. Second, non drug hemp has gained a reputation for being highly environmentally friendly, and it has become a hallmark of organic agriculture. Third, there has been an increasing acceptance of marijuana's mainstream commercial usage in most of Western culture, as shown by a romanticized, idealized portrayal in the media, less zealous law enforcement, and even de facto decriminalization in certain jurisdictions. Fourth, the use of marijuana prescribed for medicinal uses has increased significantly. Many states have decriminalized cannabis for commercial hemp, medicinal marijuana, and recreational marijuana as a consequence of sociological, philosophical, legislative, and legal developments—complex and controversial topics that we can only touch on briefly.

The Resurrection of Industrial Hemp

The non-drug fiber and oilseed uses of C. sativa were generally regarded as outdated by the mid-twentieth century, with no fair scope for legal production. Furthermore, the problems of recreational and medicinal applications of Cannabis made fair consideration of the redevelopment of industrial hemp for reasons that everybody can accept are not dangerous quite difficult. Human rights in democratic countries is severely restricted, indicating the level of animosity toward even innocuous forms of C. sativa. Before the Queensland Parliament declared changes to the Drugs Misuse Act 1986 on September 27, 2002, it was illegal to simply publish or possess information on increasing industrial hemp in Queensland, Australia (Olsen 2004). For at least a half-century of complete prohibition, most Western countries saw the reintroduction of nonintoxicating hemp production at the turn of the twenty-first century. The cultivars approved are deemed safe enough to be grown for the production of fiber and oilseed products (generally under license). Fears that acceptance of the new crop will (1) be seen by the public as de facto acceptance of the legitimacy of all aspects of the species C. sativa, (2) function as a stepping stone to the legalization of marijuana, (3) stymie the war on drugs, and (4) necessitate costly monitoring to ensure that licensed crops are treated according to regulations caused the delay in reauthorizing hemp cultivation. When it became clear that hemp farming was being encouraged in the last decade of the twentieth century, numerous economic studies were performed in different countries (Riddlestone et al. 1994; Gehl 1995; McNulty 1995; Ehrensing 1998; Kraenzel et al. 1998; Marcus 1998; Pinfold Consulting 1998; Thompson et al. 1998; Johnson 1999). Since hemp production has been resurrected in many countries, and the resulting hemp goods have been tested in the marketplace over the past two decades, these studies are more or less outdated. A more recent study of fiber capacity by Fortenbery and Bennett (2004) is more hopeful of future growth. The potential in Kentucky is explored by Robbins et al. (2013), and the potential in the United States is examined by Johnson (2015); all reviews are somewhat more positive. With the significant exception of the United States, hemp is now cultivated commercially in around three dozen countries (although this seems about to change). Earlier economic studies typically failed to predict that hempseed applications would become the most exciting feature of industrial hemp production, rather than fiber applications. In the last two decades, a plethora of creative, revolutionary hemp fiber and hempseed goods have emerged on the market, providing significant impetus to growing industries (Small and Marcus 2002).

Hemp vs. Marijuana

C. sativa was selected specifically for three reasons, as previously stated: fiber (from the stem bark), edible seeds and seed oil, and intoxicating preparations (mostly from the flowering parts of the female plants). The generic names "hemp" and "marijuana" (much less frequently spelled marihuana) have been vaguely applied to all three groups, though traditionally, "hemp" has been used primarily for the fiber kind of plant as well as for its harvested fiber, and "marijuana" has been used primarily for the drug kind as well as for drug preparations made from it. Because of the long-held stigma associated with illegal drugs, companies dealing with non-intoxicating applications for fiber and oilseed have worked hard to distinguish themselves from marijuana uses of C. sativa. They make a point to stress that “hemp is not marijuana.” The word "industrial hemp" has been used to differentiate plants licensed for non-psychoactive drug uses (both fiber and oilseed). Industrial hemp is a term that is now widely used to describe C. sativa fiber and oilseed cultivars that have very little THC.

Image by Jeff W

Figure 7

Medical Cannabis pre-rolls

The Resurrection of Medical Cannabis

Cannabis has been used for medicinal purposes since ancient times. Throughout much of the twentieth century, cannabis was illegal, which hampered study and advancement of treatments. Ironically, the use of black market marijuana by thousands of people suffering from a number of illnesses confirmed that cannabis can help ease symptoms, causing valiant attempts by patients, physicians, social advocates, and lawyers to make medical marijuana legal. Medical marijuana is now legal in a number of states, and its use is increasingly growing in Western countries. There have been significant developments in scientific knowledge of how cannabis influences human physiology over the past few decades, and novel medicinal drugs and innovations are either in development, being studied, or being recognised as effective in certain cases.

 

The medicinal literature has grown to be incredibly dense, and there is little consensus on the efficacy of cannabis in treating specific ailments. Indeed, there is a lot of controversy about whether or not using medical marijuana on most medical conditions is a safe idea. Regardless of the medical profession's majority opinion, medicinal marijuana has been extraordinarily commercialized in several jurisdictions, with the establishment of so-called medical dispensaries (Figure 7) that are more akin to pharmacies than hospitals, and certain doctors selling medical marijuana in a manner akin to street drug dealers. These shady trends, which represent a lack of proper regulatory preparation, will be addressed later.

The Resurrection of Recreational Cannabis

Cannabis is still heavily criminalized, especially in some Asian countries where it is punishable by death. The majority of the Western world bans marijuana use for recreational uses, but Uruguay and some U.S. states have legalized it, and other nations, especially in the Americas, are likely to follow suit. Recreational marijuana has been de facto legal in the Netherlands for decades (Figure 8), despite the fact that it is not legally recognized. There has been a general softening of sanctions, or at least of punishment, in democratic countries, coinciding with growing public awareness of illegal use. However, there is already a lot of debate and confusion on when and how existing prohibitions on recreational marijuana can be changed. Complicating matters, investment in the legal marijuana industry is generally regarded as highly lucrative, and market pressures are pushing trends. 

Figure 8

Dutch Cannabis "Coffeeshop"

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Cannabis at the Crossroads of Science and Public Policy

There would be no interest in regulating marijuana and its products if it weren't for its well-known use as an illegal drug. Its potential would have been well studied by now. However, most of this potential has only recently been analyzed, and even more has not been studied at all. It's also worth noting that humans understand not only empirical data, but also whether the possible consequences of applying that knowledge are, on average, beneficial. Simply put, can the unavoidable risk from loosening cannabis laws overshadow the future benefits? Speed limits on automobiles serve as a useful analogy (World Health Organization 2014). A one-kilometer rise in average speed raises deaths by 4% to 5%. A person hit by a car driving at 50 km/h has an 85% chance of dying, whereas a person hit by the same car traveling at 30 km/h has just a 5% chance of dying. Speed is responsible for about 30% of traffic accidents in high-income countries. Many methods are used to recognize the risks of vehicle speed—education, police law control, speed zones, speed traps, speed bumps, and road designs that distinguish vehicles from pedestrians and bicyclists—to name a few. Grandstanding leaders invariably excel in bringing traffic to a halt at intersections where an infant has been killed by an irresponsible driver, and protecting vulnerable communities must surely be a top priority. Yet, in the end, it is human psychology on a much larger scale that dictates how far cars go and, most specifically, whether people follow every rule. People follow laws for two reasons: (1) to escape legal consequences and fines, and (2) because they believe the laws are legitimate (Tyler 1990). Present drug laws are commonly disregarded and disobeyed, resulting in immense societal financial and personal expenses. Much like driving speed limits must be established based on what the majority of citizens would willingly comply, even though it induces some unintended damage, cannabis legislation must be changed to represent not only "the truth," but also shifting popular sentiment.

Prehistory & Early History

Prehuman and Early History of Cannabis sativa

Cannabis Sativa's Family Tree and Pre-Human Origins

Cannabis sativa, commonly known as marijuana, has a long and rich history, dating back thousands of years. However, the plant's evolution and early history remain somewhat mysterious, as there is a lack of definitive archaeological evidence. Nonetheless, researchers have pieced together a picture of how cannabis may have evolved and spread throughout the world.

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Cannabis sativa is an angiosperm, which is a type of flowering plant that dominates the Earth's surface. While there is some evidence of an earlier history, most fossil evidence shows that flowering plants originated about 125 million years ago in the Lower Cretaceous geological period and were diversifying into modern plant families by the Middle Cretaceous, around 100 million years ago.

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Cannabis and Humulus are the two genera that typically make up the Cannabaceae family (Small 1978a). Grudzinskaya (1988) divided Humulus into two genera and added the extinct genus Humulopsis to the Cannabaceae (although only Humulus is currently accepted). Humulus plants are vines that can be isolated easily from Cannabis. The fruits (achenes) are, however, very similar and may be mistaken for one another. For the family, older documents commonly use the outdated orthography Cannabiaceae and Cannabiaceae (Miller 1970).

According to recent molecular data, the Cannabaceae family can be divided into around ten genera (Sytsma et al. 2002; Yang et al. 2013; Figure 2.1). On the basis of parasitic relationships in Cannabis and related families, McPartland and Guy (2004a) proposed that the Cannabaceae lineage originated no more than 34 million years ago. However, except for pollen grains, there are no fossils dating back millions of years to when C. sativa first evolved, and its age has not been reliably determined.

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Despite the lack of direct evidence, researchers believe that cannabis may have evolved in the Central Asian region, specifically in the foothills of the Himalayas. The plant likely spread throughout Asia and the Middle East, where it was cultivated and used for various purposes. For example, in ancient China, hemp was used for making paper, clothing, and rope, as well as for medicinal purposes.

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In the Indian subcontinent, cannabis has been used for thousands of years in Ayurvedic medicine, a traditional system of medicine that originated in India. The earliest written reference to cannabis use in India dates back to 2000 BCE in the Atharvaveda, one of the four sacred texts of Hinduism. In these texts, cannabis is referred to as a sacred plant and is associated with the god Shiva.

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In addition to its use in traditional medicine and spiritual practices, cannabis was also used as a psychoactive drug. In ancient Greece, cannabis was used as a remedy for earache, edema, and inflammation. The Greek historian Herodotus wrote about the Scythians, a nomadic tribe from Central Asia, who would inhale the smoke from burning cannabis seeds and flowers in order to achieve a trance-like state.

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Overall, the early history of cannabis is complex and multifaceted. While much remains unknown, it is clear that the plant has played an important role in human societies for thousands of years, serving a variety of purposes ranging from medicine and spirituality to recreation and commerce.

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Figure 9

Distribution of archaeological evidence of Cannabis in prehistory worldwide

Evolutionary History of Cannabis

The evolution of angiosperms, or flowering plants, is a complex and fascinating topic that spans over millions of years. During the Lower and Middle Cretaceous periods, which began approximately 145 million years ago and lasted until 100 million years ago, angiosperms began to diversify and dominate the plant world. This period is often referred to as the "Age of Angiosperms" due to the rapid expansion and diversification of this group of plants (Wang et al., 2020).

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One of the families that evolved during this time period is the Cannabaceae family, which includes the two typical genera, Cannabis and Humulus. The Cannabaceae family is believed to have originated in the Early Cretaceous period, around 100 million years ago (Chen et al., 2019). However, the family only began to diversify and spread in the Late Cretaceous and early Paleogene periods, between 65 and 50 million years ago (Chen et al., 2019).

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Humulus and Cannabis plants share many similarities, particularly in their fruits. Both genera produce cone-like structures that are covered in small, resinous glands. In Humulus, these cones are commonly referred to as "hops" and are used in the production of beer, while in Cannabis they are known as "buds" and contain the plant's psychoactive compounds.

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In older documents, the Cannabaceae family was often referred to as the "Urticaceae-Moraceae-Humuli" complex due to its perceived similarity to these families (Small, 2015). However, recent molecular data has shown that the Cannabaceae family is distinct and should be classified separately (Chen et al., 2019). This molecular data also divides the family into around ten genera, including Cannabis, Humulus, and the extinct genus Humulopsis (Chen et al., 2019).

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Scientists estimate that the appearance of the Cannabis species occurred around 20 million years ago, according to various studies that utilize DNA molecular phylogenies calibrated with related genera fossils. Different estimates have been proposed, ranging from 18.2 to 27.8 million years ago. The oldest known pollen compatible with Cannabis was found in rocks in the NE Tibetan Plateau, which is currently Ningxia, China, dating back to 19.6 million years ago. This leads McPartland and colleagues to suggest that this area was the center of origin for Cannabis.

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Fossil records of pollen and seeds reveal that wild Cannabis had already spread from its centre of origin to Europe and East Asia long before modern humans inhabited these regions, dating back around two million years. Variations in habitat range during glacial and interglacial periods could have contributed to Cannabis diversification before human intervention.

Cannabis in Prehistory

Cannabis is a plant with a long and complex history, both in terms of its cultivation by humans and its role in human societies. Recent genetic studies have shed new light on the origins and spread of cannabis, revealing a complex history of hybridization and adaptation.

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One study published in the journal Science Advances found that cannabis likely originated in the Tibetan Plateau region, with the plant then spreading to different parts of the world over time. The study's authors analyzed the genomes of over 100 different cannabis strains and found that the plant's genetic diversity was highest in central Asia, suggesting that this is where it first evolved.

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Another study, published in the journal Nature Ecology & Evolution, suggested that cannabis was domesticated in what is now northwest China around 12,000 years ago. The study's authors analyzed the genomes of 82 different cannabis strains and found that the plant's genetic diversity was lowest in this region, suggesting that it was a center of domestication.

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The domestication of cannabis likely occurred in a similar way to other crops, such as wheat and maize. Early humans would have observed that certain plants produced better results than others and selectively bred them to create stronger strains that were more effective in treating various ailments.

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Archaeological evidence suggests that early humans may have used cannabis for medicinal purposes. For example, a study published in the journal Vegetation History and Archaeobotany found evidence of cannabis pollen in the soil of a burial site in China dating back to the Neolithic period, around 5000 BCE. While it is difficult to determine whether cannabis was used for psychoactive purposes during this time, it is clear that the plant had some medicinal value.

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One scenario in which cannabis may have been domesticated is as follows: early humans who were using cannabis for medicinal purposes would have observed that certain plants produced better results than others. They would then have selectively bred these plants to create stronger strains that were more effective in treating various ailments.

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Cannabis pollen has been discovered in prehistoric sites such as the Altai Mountains in Siberia and the Yanghai Tombs in China. While it is possible that the presence of cannabis pollen at these sites was due to intentional use, it is also possible that the pollen was simply carried by the wind or other environmental factors.

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In contrast, the discovery of cannabis pollen in sediment in Madagascar is more likely to have been intentional, as the plant is not native to the island. This suggests that early humans may have intentionally brought cannabis to Madagascar, possibly as a medicinal plant or for other purposes.

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The use of cannabis fibers in prehistoric textiles and ropes is also worth exploring. According to a study published in the journal Economic Botany, cannabis fibers were used in prehistoric textiles and ropes by early Austronesian cultures. It is believed that these early seafaring peoples spread cannabis along with other domesticated plants as they migrated across the Pacific.

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The spread of domesticated plants within the context of early trade networks in the Indo-Pacific and what would become the Silk Road is also worth considering. According to a study published in the journal Antiquity, early trade networks in the region facilitated the spread of various domesticated plants, including cannabis, across the continent. As trade networks expanded and became more complex over time, so too did the spread of domesticated plants.

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The spread of cannabis throughout the world has been closely tied to its various uses, both medicinal and recreational. In many parts of the world, cannabis has been used for centuries as a medicine, with early texts describing its use for everything from pain relief to treating malaria.

Cannabis in Early Human History

For over a dozen millennia, cannabis has shared a fascinating history with humanity, deeply embedded in our ancestral cultures. This versatile plant played a pivotal role in the development of human civilization, providing food, fibres, and entheogenic substances. However, due to centuries of human intervention, it's challenging to determine its original range and understand its domestication process.

Despite this mystique, recent advances in molecular, pollen, fossil, and archaeobotanical data have made it possible to disentangle this complex relationship. By utilizing these techniques, we can better understand the evolution of this ancient plant and its profound impact on human history.

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In this discussion, we will focus on the domestication and early use of cannabis in different cultures, starting from its region of origin, and then move on to other regions where the plant was likely acquired via trade.

The Domestication of Cannabis

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Cannabis is a unique crop with a fascinating history of association with humans. Some scholars propose that it was initially a "camp follower" plant, following the nomadic lifestyle of our primordial ancestors. As they moved between temporary camps, they created clearings and paths in the vegetation, often near bodies of water, where soils would be enriched with organic materials. Cannabis likely took advantage of this niche, and the plant's current habitat supports this theory. Wild Cannabis can be found growing in clearings, where competition is limited, and soils are continuously moist but well-drained.

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It is plausible that a plant with multiple uses growing near camps was a valuable resource for early humans. It is unclear how long this interaction lasted, but as populations settled and expanded, the natural populations of Cannabis were likely depleted. This prompted early farmers to start actively sowing seeds, selecting seeds from better plants with larger seeds, taller stalks, and more resin production. This initiated the process of active domestication, leading to the development of the Cannabis we know today.

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There are numerous theories about the time and location of Cannabis domestication, and the evidence is complex and sometimes contradictory. Pollen fossils reveal that wild Cannabis was prevalent in Eurasia for millions of years, but it is difficult to determine exactly where and when it was first cultivated by humans. Depending on the studies considered, different hypotheses may seem more credible than others, and interpreting the evidence from thousands of years ago will inevitably involve some degree of speculation. Therefore, it is important to adopt a holistic approach, evaluate the evidence with a critical eye, and keep an open mind when trying to piece together the puzzle of Cannabis domestication.

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The earliest known use of hemp fiber in Europe dates back to the Gravettian culture in the Czech Republic around 27000 years ago. It is likely that nomadic tribes had been using wild Cannabis for a long time, but domestication did not occur until cultivation practices spread from the Middle East into Europe. Pollen and archaeological records suggest that Cannabis was present in its wild form throughout most of Europe between 12000-6000 years ago, with the highest concentration found in the regions north and west of the Black Sea.

Evidence of Cannabis smoking in Europe was discovered in a clay vessel with carbonized seeds from a tomb in Romania dated 5300-4300 years ago, while hemp fibers were found preserved at a site near Lake Varna in Bulgaria dated 4200 years ago. The first evidence of Cannabis cultivation in Europe was detected in a spike of Cannabis pollen in Lake Varna between 7000 and 5000 years ago. From this area, Cannabis cultivation spread across the entire European continent between 4500 and 2300 years ago.

According to archaeological records, hunter-gatherer communities used wild Cannabis as a source of food, fiber, and entheogen during Mesolithic and Neolithic times. Around 7000-5000 years ago, cultivation and likely domestication occurred around the Black Sea. McPartland and Hegman suggest that Cannabis dispersed from Asia to Europe in its wild form during the Pleistocene.

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In contrast to the theory of European domestication, some researchers suggest that Cannabis was actually domesticated in Central Asia, specifically in present-day Mongolia and northern China, around 12,000-10,000 years ago. This is the most widely accepted hypothesis, according to Vavilov (1992) and Crawford (2006).

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A recent molecular study by Ren et al. (2021) estimated that the ancestors of hemp and drug types diverged from wild Cannabis between 15,728 and 6,458 years ago, indicating a multistep domestication process with ongoing introgression of wild/feral genes into both hemp and drug types populations. Archaeological evidence from East Asia also supports the presence of Cannabis seeds and fibers dating back to 7,000-5,000 years ago (Zhang & Gao, 1999; Zhou 1980; Yin, 2003), with some sites showing evidence of domestication (e.g., seed enlargement, loss of abscission zone).

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Zhou et al. (2011) found domesticated Cannabis seeds at a site associated with the YÇŽngsháo culture (7,000-5,000 years ago) in northern China, and there is a significant increase in seed records in the following millennia (5,000-4,000 years ago). The genomic analysis by Ren et al. (2021) suggests that only a small number of early domesticated Cannabis populations expanded to form hemp and drug types around 4,000 years ago, coinciding with a rise in archaeological evidence of fiber artifacts in East Asia, the Middle East, and Europe.

Therefore, Ren et al. (2021) propose an early domestication of Cannabis in East Asia around 10,000 years ago, followed by a spread of domesticated plants around 4,000 years ago towards the Middle East and Europe.
 

The study of pollen fossils and archaeological evidence suggests that wild Cannabis was present across Eurasia millions of years ago, while early Asian and European records from 10,000 years ago indicate an earlier use of the plant. The domestication of Cannabis may have been a natural step in coevolution, linked to the spread of agricultural practices and a shift from nomadic to settled lifestyles. Cannabis, growing in the vicinity of camps in its wild form, was a useful commodity for nomadic communities.

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However, the domestication of Cannabis is a complex process that may have occurred in waves, linked to various cultural groups in the area. Molecular analysis suggests that Cannabis populations may have cycled through periods of cultivation and feral growth.

Although Ren et al. 2021 propose a single Asian domestication hypothesis, their genomic data suggests that Asian-domesticated cultivars may have migrated towards the Middle East and Europe. It is possible that domesticated cultivars of European origin were lost or hybridized long ago.

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The molecular data from Ren et al. 2021 only estimated the time of domestication, not its location. The current distribution of wild Cannabis populations provides a likely domestication area, but this may not be accurate. The domestication center of a crop may not correspond with its modern center of biodiversity, as shown in studies of Asian rice (Fuller 2011).

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Despite attempts to provide comprehensive evidence for Cannabis domestication, it is a complex topic, and recent data suggests that the discussion is more open than ever. Archaeobotanical studies using pollen, seeds, and fibers suggest that there may be at least two domestication centers for Cannabis, one in Europe and one in Asia.

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Cannabis in Ancient East Asia

Cannabis has a long and complex history in East Asia, with evidence of its use dating back thousands of years. The plant was utilized for a variety of purposes, including for fiber, food, medicine, and religious rituals. We will explore the early history of cannabis in East Asia, focusing on the regions encompassed by the modern nations of China, Korea, and Japan.

China

The early history of Cannabis in China can be traced to

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Korea

Japan

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Cannabis History

Cannabis throughout History

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Cannabis in India

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Cannabis Biology

Anatomy of a Cannabis Plant

What does Cannabis look like?

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The cannabis plant has several structures that are similar to those found in other flowering plants. It typically grows on long, slender stems with large fan leaves that extend out from points called nodes.

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The most striking feature of the cannabis plant is its flowers, or buds, which have unique and intricate formations: fiery orange hairs, sugary crystals, and chunky buds surrounded by small leaves. These structures contain the majority of the plant's cannabinoids and terpenes, which are responsible for its medicinal and recreational properties.

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The lifecycle of a Cannabis plant

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The life cycle of a Cannabis plant can be divided into 4 stages:

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  1. Germination: This is when the seed sprouts and emerges from the soil, which usually takes around 3-10 days.

  2. Seedling: After the seedling emerges, the plant will grow its first set of cotyledon leaves. This stage typically lasts for 2-3 weeks.

  3. Vegetative: During this stage, the plant will begin to grow its stalks, branches, stems, and fan leaves. This stage can last anywhere from 3 to 16 weeks, depending on the strain and growing conditions.

  4. Flowering: This is the stage when the plant begins to produce buds. Flowering can take anywhere from 8-11 weeks, again depending on the strain and growing conditions.

Cannabis_sativa_Koehler_drawing.jpg

Figure 1

Cannabis Sativa L. Botanical Illustration From Franz Eugen Köhler's Medizinal-Pflantzen. Published and copyrighted by Gera-Untermhaus, FE Köhler in 1887 (1883–1914)

fig1.5 Female flower with bract

fig1.6 Female flower

fig1.7 Female fruit cluster

fig1.8 Fruit (Achene) with perigonal bract

fig1.9 Achene, wide (flat) side view

fig1.10 Achene, narrow side view

Seeds

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Anatomy of a Cannabis Seed:

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Cannabis achenes, also known as seeds, are a crucial component of the cannabis plant's reproductive system. Achenes are the ripened ovaries of the female cannabis flower, which contain the genetic material necessary to produce a new cannabis plant.

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Cannabis seeds are small, oval-shaped structures, measuring about 3-4mm in length and 2mm in width. They are covered by a thin, hard, outer layer called the seed coat, which is light brown in color and has distinctive markings that are unique to each strain. The seed coat protects the embryo, which is the young cannabis plant, and the endosperm, which is the nutrient-rich tissue that provides food for the embryo during germination.

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The embryo is made up of a radicle, a hypocotyl, and a plumule. The radicle is the first part of the plant to emerge from the seed and eventually becomes the root system. The hypocotyl is the part of the stem that connects the radicle to the plumule, which is the young shoot that will develop into the cannabis plant's foliage.

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Function of Cannabis Achenes:

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The primary function of cannabis achenes is reproduction. When a female cannabis plant is pollinated by a male plant, the male plant's pollen grains fertilize the female plant's ovules, which are located inside the pistil of the female flower. The fertilized ovules then develop into achenes, which contain the genetic material necessary to produce a new cannabis plant.

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In addition to reproduction, cannabis achenes are also essential in the cannabis industry. They are the source of the seeds that growers use to cultivate new cannabis plants, and they also contain valuable compounds, such as essential fatty acids and proteins, that are used in a variety of products, including food, cosmetics, and pharmaceuticals.

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Roots

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Roots are a crucial component of the cannabis plant's structure and function. They are responsible for anchoring the plant in the soil, absorbing water and nutrients, and providing support for the plant's above-ground structures.

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Anatomy of Cannabis Roots:

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Cannabis roots are complex structures that consist of several different types of tissue, each with a specific function. The primary root, also known as the taproot, is the first root that emerges from the seed and is responsible for anchoring the plant in the soil. The taproot is typically long and thick and can reach depths of several feet in some cannabis strains.

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As the plant grows, lateral roots emerge from the taproot and spread out in all directions, forming a dense network of roots that can extend several feet in all directions. These lateral roots are responsible for absorbing water and nutrients from the soil and transporting them to the rest of the plant.

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The root system is also divided into two regions, the root cap, and the root meristem. The root cap is the tip of the root and is responsible for protecting the delicate meristem tissue as it grows through the soil. The root meristem is the region of the root where cell division and growth occur, and it is responsible for generating new root tissue.

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Function of Cannabis Roots:

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The primary function of cannabis roots is to absorb water and nutrients from the soil and transport them to the rest of the plant. Roots use a process called osmosis to absorb water, and they also absorb essential nutrients, such as nitrogen, phosphorus, and potassium, through tiny root hairs that extend from the lateral roots.

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Roots also play a crucial role in the plant's structural support. The taproot provides a stable anchor for the plant, while the lateral roots help to stabilize the plant and prevent it from being uprooted by wind or other environmental factors.

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Stems

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Stems are one of the three main parts of the cannabis plant, along with roots and leaves. The stem is the part of the plant that supports the leaves, flowers, and buds and transports water, nutrients, and other essential compounds throughout the plant.

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Anatomy of Cannabis Stems:

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Cannabis stems consist of several different types of tissue, each with a specific function. The outermost layer of the stem is the epidermis, which is a thin layer of cells that protect the underlying tissues from damage and moisture loss. Beneath the epidermis is the cortex, which is the primary storage tissue in the stem and contains cells that store starches, oils, and other compounds.

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The vascular tissue is the part of the stem responsible for transporting water and nutrients throughout the plant. This tissue consists of two types of cells: xylem and phloem. Xylem cells transport water and dissolved minerals from the roots to the rest of the plant, while phloem cells transport sugars and other organic compounds from the leaves to the rest of the plant.

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The innermost layer of the stem is the pith, which is a spongy tissue that stores water and functions as a support structure for the stem.

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Function of Cannabis Stems:

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The primary function of cannabis stems is to support the leaves, flowers, and buds and transport water, nutrients, and other essential compounds throughout the plant. The stem's vascular tissue plays a critical role in this function, transporting water and nutrients from the roots to the rest of the plant and sugars and other organic compounds from the leaves to the rest of the plant.

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Stems also play a crucial role in the plant's structural support. The stem's pith and cortex provide structural stability, while the stem's epidermis protects the underlying tissues from damage and moisture loss.

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Nodes

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In cannabis plants, nodes are the points on the stem where the leaves and branches emerge. These nodes are important for the plant's growth and development and play a crucial role in determining the shape and size of the plant.

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Anatomy of Cannabis Nodes:

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At each node, the stem of the cannabis plant has a small bump called the axillary bud. This bud contains a small cluster of undifferentiated cells that can potentially develop into new branches or flowers. The axillary bud is covered by small, green, leaf-like structures called bracts, which protect the developing bud.

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Function of Cannabis Nodes:

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The nodes of the cannabis plant serve several important functions. Firstly, they are the points where the plant's leaves and branches emerge from the stem. This branching pattern determines the overall shape and size of the plant and affects its ability to produce large, healthy buds.

Nodes also play a critical role in the plant's reproductive cycle. The axillary buds at each node have the potential to develop into new branches or flowers, which are essential for the plant's ability to reproduce and produce new generations of plants.

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Finally, nodes are important for the plant's ability to respond to environmental stressors. When a cannabis plant is exposed to stressors such as high temperatures, drought, or pest infestations, the axillary buds at each node may begin to develop more rapidly in an effort to produce new leaves and branches that can help the plant to cope with the stress.

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Petiole

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The petiole is a thin stem-like structure that attaches the leaf blade or leaflet to the main stem of a cannabis plant. It provides a structural connection between the leaf and the stem, allowing the leaf to receive nutrients and water from the stem and transport the products of photosynthesis back to the stem and other parts of the plant.

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Anatomy of Cannabis Petioles:

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Cannabis petioles are usually green or brown in color and can range in length depending on the strain and the age of the plant. They are made up of a bundle of vascular tissues, including xylem and phloem, which are responsible for the transport of water and nutrients throughout the plant.

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The petiole also contains a small structure called the pulvinus, which is located at the base of the petiole where it attaches to the stem. The pulvinus is a specialized plant tissue that allows the leaf to move in response to changes in light, temperature, and other environmental factors.

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Function of Cannabis Petioles:

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The primary function of cannabis petioles is to provide a structural connection between the leaf and the stem of the plant. They allow the leaf to receive nutrients and water from the stem and transport the products of photosynthesis back to the stem and other parts of the plant.

In addition to their structural role, petioles can also play a role in regulating the growth and development of the plant. For example, by removing petioles from lower leaves, growers can redirect energy and nutrients to other parts of the plant, such as the buds, resulting in increased yields.

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Cotolydon

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Cotyledons are embryonic leaves that are present in the seeds of most plants, including cannabis. These small, usually oval-shaped structures are the first leaves to emerge from the seed during germination, and they play a critical role in providing the developing seedling with the nutrients it needs to grow and develop.

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Anatomy of Cannabis Cotyledons:

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In cannabis plants, each seed contains two cotyledons, which are attached to the embryonic stem. The cotyledons are rich in nutrients and contain a reserve of starches, proteins, and other compounds that provide the developing seedling with the energy it needs to grow and develop until it can produce its own energy through photosynthesis.

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Function of Cannabis Cotyledons:

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The primary function of cannabis cotyledons is to provide the developing seedling with the nutrients it needs to grow and develop until it can produce its own energy through photosynthesis. During germination, the cotyledons absorb moisture from the surrounding soil and use it to initiate metabolic processes that convert the stored nutrients into energy that can be used by the growing plant.

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Once the seedling has developed enough leaves to begin photosynthesis, the cotyledons are no longer needed and will eventually wither and fall off.

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Leaves

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Leaves are one of the most recognizable and important parts of a cannabis plant. They play a critical role in photosynthesis, the process by which plants convert light energy into chemical energy that can be used for growth and development.

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Anatomy of Cannabis Leaves:

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The leaves of a cannabis plant are typically palmately compound, meaning they are divided into multiple leaflets that are arranged around a central point. The number of leaflets can vary depending on the strain and the age of the plant, but most cannabis leaves have five to seven leaflets.

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Each leaflet is attached to a petiole, a thin stem that connects the leaflet to the main stem of the plant. The surface of the leaf is covered with tiny pores called stomata, which allow the plant to exchange gases with the surrounding environment. The underside of the leaf is usually a lighter color than the top and may be covered with fine hairs.

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Function of Cannabis Leaves:

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The primary function of cannabis leaves is to carry out photosynthesis, the process by which plants use light energy to produce glucose and other organic compounds. During photosynthesis, the plant takes in carbon dioxide through its stomata and uses energy from sunlight to convert it into sugar.

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In addition to photosynthesis, leaves also play a critical role in transpiration, the process by which plants lose water through their stomata. This helps to regulate the plant's internal water balance and prevent wilting.

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Leaves also serve as a site for the production of secondary metabolites, such as cannabinoids and terpenes, which give cannabis its unique aroma, flavor, and therapeutic properties.

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Female and Male plants

 

Cannabis is a dioecious plant, meaning that it has separate male and female plants. This is in contrast to monoecious plants, which have both male and female reproductive organs on the same plant.

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How to determine the sex of a Cannabis plant?

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Cannabis plants, like many other plants, have a reproductive system that determines their sex. The sex of cannabis plants is an essential factor to consider for many growers, as female plants produce the desired flowers that contain THC and other cannabinoids, while male plants produce pollen that can fertilize female plants, leading to the production of seeds.

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One of the most common methods to determine the sex of cannabis plants is to observe their pre-flowers. Pre-flowers are small, immature versions of flowers that appear on cannabis plants during the early stages of growth. They typically emerge between the fourth and sixth week of growth and can be found at the nodes where the leaves meet the main stem. By closely examining the pre-flowers, growers can identify the sex of the plant. Male pre-flowers will have a small, round, ball-like shape, while female pre-flowers will have two small, white, hair-like pistils. However, it's essential to note that pre-flowers can be challenging to distinguish, and growers need to have a keen eye and patience to identify them accurately.

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Another method to determine the sex of cannabis plants is through genetic testing. This method involves sending a sample of the plant's DNA to a lab, which will analyse it to determine its sex. Genetic testing is a highly accurate method to determine the sex of cannabis plants, as it can identify the plant's sex even before it starts to show any physical signs of its gender. However, this method can be expensive and time-consuming, and it's usually reserved for breeders and growers who require a high degree of accuracy in their crops.

 

Trichomes

 

Trichomes are tiny hair-like structures that are found on the surface of the cannabis plant. They can be found on various parts of the plant, including the leaves, stems, and flowers, and they play a crucial role in the production of cannabinoids, terpenes, and other compounds that give cannabis its unique properties.

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Trichomes are composed of a stalk and a gland head, and they come in a variety of shapes and sizes depending on the strain and stage of growth. The gland head is the part of the trichome that contains the resinous material, which is rich in cannabinoids and terpenes. When trichomes are fully mature, they appear as small, crystal-like structures that sparkle in the light.

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The primary function of trichomes is to protect the cannabis plant from environmental stressors such as UV radiation, pests, and pathogens. They also help to regulate moisture levels and prevent water loss, and they may even play a role in attracting beneficial insects that can help to ward off pests.

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In addition to their protective function, trichomes are also responsible for the production of the cannabinoids and terpenes that give cannabis its unique properties. Cannabinoids such as THC and CBD are synthesized within the gland heads of the trichomes, and terpenes are produced in the same area. The size, density, and abundance of trichomes can affect the potency and flavour profile of the cannabis plant.



Calyx

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The calyx is a small, leaf-like structure that surrounds the ovule and the stigma of the female cannabis plant. It is typically green in colour and covered in tiny hairs called trichomes, which are responsible for producing and storing the resin that contains cannabinoids and other compounds.

 

The calyx serves several important functions in the female cannabis plant:

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  1. Protection: The calyx provides protection for the developing ovule and reproductive structures inside the flower cluster. It helps to shield the plant from environmental stressors and predators, such as insects and animals.

  2. Pollination: The stigma of the female cannabis plant is located within the calyx and is responsible for capturing pollen from male plants during fertilization. The calyx helps to protect the ovule and the stigma from contamination, ensuring successful pollination and reproduction.

  3. Resin production: The calyx is where the majority of the plant's resin is produced. Trichomes on the surface of the calyx contain high concentrations of cannabinoids and terpenes, which are responsible for the plant's therapeutic and recreational properties. As the plant matures, the calyxes swell and become more pronounced, indicating that the flowers are ready for harvest.

  4. Attraction: The resin produced by the calyx also serves to attract pollinators, such as bees and other insects, which help to ensure successful fertilization and reproduction.

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Bracts

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Bracts are modified leaves that protect the developing flower bud of the cannabis plant before it opens. They are typically larger and more colourful than normal leaves, and may be covered in trichomes (small, hair-like structures) that contain high concentrations of cannabinoids and terpenes.

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In the case of cannabis, the bracts are often mistaken for the flowers themselves, as they are the most visible part of the plant's reproductive structures. However, the true flowers of the female cannabis plant are located within the bracts and are known as the calyxes. The calyxes contain the ovules and stigmas that are necessary for reproduction, as well as the trichomes that produce the plant's therapeutic and recreational properties.

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As the female cannabis plant matures, the bracts will open to reveal the calyxes within. At this point, the plant is typically ready for harvest, as the calyxes will be swollen and coated in resin. The bracts themselves are not typically harvested for use, as they do not contain the same concentrations of cannabinoids and terpenes as the calyxes.

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Ovules

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In botany, an ovule is a structure that is part of the female reproductive system of seed plants, including cannabis. The ovule contains the female gametophyte, which produces the egg cell that is fertilized by the male gametophyte (pollen) during sexual reproduction. Once fertilized, the ovule develops into a seed, which contains the genetic material necessary for the development of a new plant.

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In the case of the female cannabis plant, the ovules are located within the calyxes of the flowers. The calyxes, which are protected by bracts, contain the ovules and the stigma, which is the female reproductive organ that captures the pollen from the male plants during fertilization.

If fertilized, the ovule will develop into a seed, which contains the genetic material necessary for the development of a new plant. If the ovule is not fertilized, it will eventually wither and fall off the plant.

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Stigma

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The stigma is a specialized structure that is part of the female reproductive system of flowering plants, including cannabis. The stigma is the uppermost part of the pistil, the female reproductive organ of the flower, and is responsible for capturing the pollen from the male plants during fertilization.

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In the case of the female cannabis plant, the stigma is located at the top of the calyx, which is the structure that surrounds the ovule. The stigma is covered in small, hair-like structures called papillae, which are responsible for trapping and holding onto the pollen.

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Once the pollen has been captured by the stigma, it will begin to grow a tube that extends down through the style, which is the long, slender portion of the pistil that connects the stigma to the ovary. The pollen tube will then reach the ovule and release the male gametes, which fertilize the female gamete and initiate the development of a new seed.

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The stigma is an essential part of the female cannabis plant's reproductive system, as it is responsible for capturing the pollen necessary for fertilization. The structure of the stigma, with its specialized papillae, is adapted to help ensure successful fertilization by holding onto the pollen and guiding it down to the ovule. Without a properly functioning stigma, the plant would not be able to reproduce and produce new seeds.

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Pistil

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In botany, a pistil is the female reproductive organ of a flower, consisting of three parts: the stigma, style, and ovary. The pistil is found in the center of the flower, and its primary function is to produce and protect the ovules, which will develop into seeds after fertilization.

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In the case of the female cannabis plant, the pistil is responsible for producing and protecting the ovules, which are contained within the calyxes. The stigma, which is the uppermost part of the pistil, is responsible for capturing the pollen from the male plants during fertilization. The style is the long, slender portion of the pistil that connects the stigma to the ovary. The ovary is the enlarged base of the pistil that contains the ovules.

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After fertilization, the ovary will develop into a fruit or seed pod that contains the newly formed seed(s). In cannabis, the seed pod is commonly known as a "bud," and is harvested for its medicinal and recreational properties.

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The pistil is an essential part of the female cannabis plant's reproductive system, as it is responsible for producing and protecting the ovules, which will develop into seeds after fertilization. The structure of the pistil, with its specialized parts, is adapted to help ensure successful fertilization by capturing and guiding the pollen down to the ovule. Without a properly functioning pistil, the plant would not be able to reproduce and produce new seeds.

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Style

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The style is the long, slender portion of the female reproductive organ (pistil) that connects the stigma to the ovary in a flower. The style is responsible for providing a pathway for the pollen tube to grow down from the stigma to the ovary, where it can fertilize the ovule and initiate the development of a new seed.

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In the case of the female cannabis plant, the style is the elongated structure that connects the stigma, which is responsible for capturing pollen, to the ovary, which contains the ovules. The style is essential for the successful fertilization of the ovules, as it provides a pathway for the pollen to reach the ovules and fertilize them.

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The length and thickness of the style can vary depending on the species and variety of cannabis. Some strains may have short, stubby styles, while others may have long, slender styles. The structure of the style is adapted to help ensure successful fertilization by providing an ideal pathway for the pollen tube to grow down to the ovary and fertilize the ovule.

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Pollen

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Pollen is a fine powdery substance that contains the male reproductive cells (gametes) of flowering plants, including cannabis. The male cannabis plant produces pollen in the form of small, yellowish balls that are found on the tips of its branches. The pollen is essential for the process of fertilization, which is necessary for the production of seeds in the female cannabis plant.

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In order for fertilization to occur, the pollen must be transferred from the male plant to the female plant. This can occur naturally through wind or insects, or through human intervention in the form of controlled breeding programs.

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Once the pollen has been transferred to the female plant, it will land on the stigma, which is the uppermost part of the female reproductive organ (pistil). The pollen will then begin to grow a tube that extends down through the style, which is the long, slender portion of the pistil that connects the stigma to the ovary. The pollen tube will then reach the ovule and release the male gametes, which fertilize the female gamete and initiate the development of a new seed.

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The structure of the pollen is adapted to help ensure successful fertilization by being light and easily transported by wind or insects. The male cannabis plant produces a large number of pollen grains to increase the chances of successful fertilization. The potency and quality of the pollen can vary depending on the genetics of the plant and environmental factors such as temperature and humidity.

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Pollen Sac

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Pollen sacs are structures found on male cannabis plants that contain the pollen grains responsible for fertilizing female plants. These sacs are located on the tips of the male plant's branches and appear as small, oval-shaped structures that can range in color from light green to yellow.

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The development of pollen sacs is triggered by a change in the light cycle, with the male plants requiring longer periods of darkness than their female counterparts. Once the plant reaches the flowering stage, the pollen sacs will begin to develop and mature over the course of several weeks.

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Pollen sacs contain thousands of individual pollen grains, which are the male reproductive cells that will fertilize the female plants. The pollen grains are released from the sacs when they become mature, and can be transferred to female plants through natural means such as wind or insects, or through human intervention in the form of controlled breeding programs.

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Once the pollen grains are transferred to the female plant, they will land on the stigma and begin to grow a tube that extends down through the style and into the ovule. The male gametes will then fertilize the female gamete, leading to the development of a new seed.

Cannabis Plant Physiology

Overview

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Cannabis physiology is the study of the internal workings of the cannabis plant, including its growth and development, metabolism, and interactions with the environment. Understanding cannabis physiology is essential for growers and researchers alike, as it allows for the optimization of cultivation practices and the development of new strains with specific characteristics.

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The cannabis plant is a complex organism that relies on a variety of physiological processes to survive and thrive. From the absorption of nutrients through the roots to the production of cannabinoids and terpenes in the flowers, every aspect of the plant's physiology plays a role in its overall health and productivity.

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By studying the various physiological processes that occur in the cannabis plant, researchers can gain a deeper understanding of how different factors, such as light, temperature, and nutrients, affect its growth and development. This knowledge can be used to develop new cultivation techniques and breeding programs that maximize yield and quality, while minimizing environmental impact.

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For growers, understanding cannabis physiology is essential for producing high-quality buds that meet the needs of consumers. By optimizing cultivation practices based on an understanding of the plant's physiology, growers can produce cannabis strains with unique flavor profiles, aromas, and effects.

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Overall, the study of cannabis physiology is a critical component of the ongoing research into this versatile plant. As new technologies and cultivation techniques emerge, a deeper understanding of the plant's physiology will be essential for ensuring the sustainable and profitable production of high-quality cannabis products.

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Growth and Development

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The growth and development of cannabis plants can be divided into several distinct stages, each with its own unique physiological characteristics. These stages include:

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A. Germination

  • Germination is the process by which a seed sprouts and develops a taproot, initiating the growth of a new plant

  • It is triggered by the presence of moisture, warmth, and oxygen

  • During germination, the seed breaks open and the radicle emerges, followed by the cotyledons and the first true leaves

  • The newly sprouted seedling relies on stored energy from the seed for growth until it can establish a connection to the soil and begin photosynthesising

B. Seedling

  • The seedling stage begins once the plant has developed its first set of true leaves, usually within the first two weeks of growth

  • During this stage, the plant is vulnerable to environmental stressors such as high temperatures, low humidity, and excess light

  • To prevent wilting or burning, seedlings should be kept in a warm, protected environment with high humidity and gentle light

C. Vegetative growth

  • Vegetative growth is the stage of growth in which the plant develops its main stems and leaves, and begins to prepare for flowering

  • During this stage, the plant requires ample light, nutrients, and water to support rapid growth

  • Photosynthesis is the primary physiological process at play during vegetative growth, as the plant converts light energy into chemical energy to fuel growth and development

  • Hormones such as auxins, cytokinins, and gibberellins play a crucial role in regulating growth and development during this stage

D. Flowering

  • Flowering is the stage of growth in which the plant begins to develop buds and produce cannabinoids and terpenes

  • It is triggered by a change in the light cycle, usually from 18 hours of light to 12 hours of light and 12 hours of darkness

  • During flowering, the plant requires different nutrients than during vegetative growth, with a higher demand for phosphorus and potassium

  • The plant also produces ethylene, a hormone that helps to regulate the timing and progression of flowering

E. Harvesting

  • Harvesting is the final stage of growth, in which the plant is harvested and prepared for consumption or processing

  • During this stage, the plant should be carefully monitored for signs of maturity, such as the development of amber trichomes

  • Harvesting too early can result in a less potent and flavourful product, while harvesting too late can result in a degradation of cannabinoids and a loss of terpenes

  • The harvested plant material should be properly cured and dried to preserve its quality and flavour

 

Environmental factors such as light, temperature, and nutrients play a crucial role in the growth and development of cannabis plants. During vegetative growth, for example, the plant requires ample light to fuel photosynthesis and promote growth, while during flowering, the plant requires a specific light cycle to trigger the onset of bud development. Temperature also plays a role in growth and development, with optimal temperatures varying depending on the stage of growth. Nutrient availability and pH levels are also important considerations, as the plant requires different ratios of nutrients during different stages of growth.

Photosynthesis

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Photosynthesis is a vital process for cannabis growth and development. It is the process by which plants convert light energy into chemical energy, which is then stored in the form of organic compounds such as sugars. Photosynthesis occurs in chloroplasts, which are organelles found in the plant cells.

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The basic equation for photosynthesis is:

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6 CO2 + 6 H2O + light energy → C6H12O6 + 6 O2

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In this equation, carbon dioxide (CO2) and water (H2O) are converted into glucose (C6H12O6) and oxygen (O2) with the help of light energy.

Chlorophyll is a green pigment found in chloroplasts that plays a crucial role in photosynthesis. There are two main types of chlorophyll: chlorophyll a and chlorophyll b. Chlorophyll a is the primary photosynthetic pigment, while chlorophyll b is an accessory pigment that helps to capture light energy.

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During photosynthesis, chlorophyll absorbs light energy and uses it to power the conversion of CO2 and H2O into glucose and O2. The light energy is absorbed by the chlorophyll molecules, which excite electrons and cause them to move through a series of electron transport chains. As the electrons move through these chains, they release energy that is used to power the synthesis of ATP (adenosine triphosphate), which is a molecule that stores energy for use by the plant.

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The process of photosynthesis is influenced by various environmental factors, such as light, temperature, and nutrients. For example, cannabis plants require a specific range of light intensity and duration for optimal photosynthesis to occur. Too much or too little light can have a negative impact on photosynthesis and overall plant growth. Temperature also plays a critical role in photosynthesis, as it affects the rate of enzyme activity and metabolic processes involved in the process. Additionally, the availability of essential nutrients, such as nitrogen, phosphorus, and potassium, is essential for healthy photosynthesis and overall plant growth.

Respiration
 

Respiration is another important process in cannabis physiology that is related to energy production. Unlike photosynthesis, which involves the conversion of light energy into chemical energy, respiration is the process by which stored chemical energy is converted into a usable form.

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The basic equation for respiration is:

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C6H12O6 + 6 O2 → 6 CO2 + 6 H2O + ATP

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In this equation, glucose (C6H12O6) and oxygen (O2) are converted into carbon dioxide (CO2), water (H2O), and ATP, which is the molecule that stores energy for use by the plant.

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There are two types of respiration in cannabis plants: aerobic and anaerobic. Aerobic respiration occurs in the presence of oxygen, and it is the primary form of respiration in healthy cannabis plants. During aerobic respiration, glucose is broken down into carbon dioxide, water, and ATP, which is then used to power various cellular processes.

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Anaerobic respiration, on the other hand, occurs in the absence of oxygen and is often referred to as fermentation. This process is less efficient than aerobic respiration, as it produces less ATP per unit of glucose. Anaerobic respiration can occur in cannabis plants under certain conditions, such as when the plant experiences oxygen deprivation due to waterlogging or other environmental stressors.

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Both aerobic and anaerobic respiration are important processes in the metabolism of cannabis plants, as they provide the energy needed for growth and development. However, aerobic respiration is the more efficient process and is essential for healthy plant growth.

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Factors such as temperature, humidity, and nutrient availability can all affect the rate of respiration in cannabis plants. For example, high temperatures can increase the rate of respiration, while low temperatures can decrease it. Similarly, a lack of oxygen or nutrients can slow down the rate of respiration and negatively impact plant growth.

Transpiration
 

Transpiration is the process by which water is transported from the roots of the cannabis plant to the leaves and other parts of the plant, where it is eventually released into the air as water vapor. This process is driven by the evaporation of water from the plant's leaves, which creates a gradient of water potential between the roots and the leaves.

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Transpiration plays a critical role in cannabis physiology, as it is responsible for the uptake of water and nutrients from the soil, as well as the transport of these resources throughout the plant. In addition, transpiration helps to regulate the temperature of the plant by releasing water vapor into the air, which cools the plant through the process of evaporative cooling.

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Several factors can affect the rate of transpiration in cannabis plants. One of the most important factors is humidity, as high humidity levels can reduce the rate of transpiration by limiting the amount of water that can evaporate from the leaves. Conversely, low humidity levels can increase the rate of transpiration, which can lead to increased water loss and potentially drought stress.

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Temperature is another important factor that can affect the rate of transpiration. High temperatures can increase the rate of transpiration, while low temperatures can reduce it. This is because high temperatures can increase the rate of evaporation from the leaves, while low temperatures can decrease the rate of evaporation and slow down the movement of water through the plant.

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Other factors that can affect the rate of transpiration include light intensity, wind speed, and soil moisture levels. For example, high light intensity can increase the rate of transpiration by increasing the temperature of the leaves and promoting evaporation, while wind can increase the rate of transpiration by increasing the rate of air flow over the leaves. Soil moisture levels are also important, as water availability can affect the rate of water uptake and transpiration in cannabis plants.

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Hormones and growth regulators

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Hormones and growth regulators are organic compounds that are produced naturally within the cannabis plant and play a critical role in regulating various aspects of plant growth and development. These compounds act as chemical messengers that signal to the plant to initiate or inhibit specific physiological processes.

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Auxins are a class of hormones that are produced in the apical meristem and are transported downward to promote cell elongation and differentiation, as well as root formation and apical dominance. The role of auxins in cannabis physiology has been well-documented, and research has shown that the application of exogenous auxins can promote the rooting of cuttings, increase the length of stems, and promote lateral branch growth.

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Cytokinins are another class of hormones that are produced in the roots and are transported upward to promote cell division and differentiation, as well as the formation of shoots and roots. In cannabis plants, cytokinins have been shown to promote the growth of lateral branches and increase the overall yield of the plant.

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Gibberellins are a group of hormones that are involved in promoting stem elongation, seed germination, and flower development. In cannabis plants, gibberellins have been shown to play a role in promoting the elongation of the stem and the growth of lateral branches. Research has also suggested that gibberellins may be involved in the regulation of flowering time and the production of trichomes.

Abscisic acid is a hormone that is involved in regulating plant responses to stress, such as drought and cold. In cannabis plants, abscisic acid is thought to play a role in regulating stomatal closure, which can help to conserve water during periods of drought. This hormone may also be involved in regulating the overall growth and development of the plant.

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Ethylene is a gas that acts as a growth regulator and is involved in regulating various aspects of plant growth and development, including fruit ripening, leaf senescence, and flower development. In cannabis plants, ethylene is thought to play a role in regulating flower development and the production of trichomes. Research has suggested that the application of exogenous ethylene can increase the overall yield of cannabis plants.

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In addition to these hormones, there are also several other growth regulators that are known to affect cannabis physiology. For example, plant growth regulators like paclobutrazol and ethephon have been shown to regulate plant growth and flowering time. These regulators can be used to promote vegetative growth, delay flowering, and increase the overall yield of the plant.

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Overall, hormones and growth regulators play a critical role in cannabis physiology by regulating various aspects of plant growth and development. Understanding how these compounds work and how they can be manipulated can help growers to optimize the growth and yield of their cannabis plants.

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Secondary Metabolites

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Secondary metabolites are organic compounds produced by the cannabis plant that are not essential to its growth and development, but rather serve a variety of functions such as defense against predators, attraction of pollinators, and communication with other organisms. The most well-known secondary metabolites in cannabis are cannabinoids, terpenes, and flavonoids.

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Cannabinoids are a class of compounds that interact with the endocannabinoid system in humans and other animals, producing various effects on the body. The most well-known cannabinoid in cannabis is delta-9-tetrahydrocannabinol (THC), which is responsible for the plant's psychoactive effects. Other cannabinoids found in cannabis include cannabidiol (CBD), cannabigerol (CBG), and cannabinol (CBN), among others. Each cannabinoid has a unique profile of effects and potential therapeutic applications.

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Terpenes are a diverse class of compounds found in many plants, including cannabis. They are responsible for the plant's distinctive aroma and flavor, as well as contributing to the therapeutic effects of the plant. Terpenes have a wide range of effects, including anti-inflammatory, analgesic, anxiolytic, and sedative properties. Some common terpenes found in cannabis include limonene, pinene, and myrcene, among others.

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Flavonoids are a class of compounds found in many plants, including cannabis. They are responsible for the plant's pigmentation and provide antioxidant and anti-inflammatory properties. Flavonoids in cannabis include quercetin, apigenin, and cannflavin A, among others. Research suggests that flavonoids may play a role in the therapeutic effects of cannabis, particularly in reducing inflammation.

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The production of secondary metabolites in cannabis is influenced by a variety of factors, including genetics, environment, and stress. For example, exposure to high levels of UV light can increase the production of cannabinoids and terpenes in cannabis, while stress from insect infestations or physical damage can increase the production of flavonoids. The specific combination and concentration of secondary metabolites in a given cannabis plant can vary widely, contributing to the diversity of effects and therapeutic applications of the plant.

Important Phytochemicals

here's a breakdown of some of the important phytochemicals found in cannabis:

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1. Cannabinoids

  • Tetrahydrocannabinol (THC)

  • Cannabidiol (CBD)

  • Cannabinol (CBN)

  • Tetrahydrocannabivarin (THCV)

  • Cannabigerol (CBG)

  • Cannabichromene (CBC)

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2. Terpenes

  • Myrcene

  • Limonene

  • Pinene

  • Linalool

  • Caryophyllene

  • Humulene

  • Terpinolene

  • Geraniol

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3. Flavonoids

  • Cannflavin A

  • Cannflavin B

  • Quercetin

  • Kaempferol

  • Apigenin

  • Vitexin

  • Orientin

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4. VSC (Volatile Sulfur Compounds)

  • Dimethyl sulfide (DMS)

  • Dimethyl disulfide (DMDS)

  • Dimethyl trisulfide (DMTS)

  • Methanethiol (MT)

  • Thiophene

  • Thioacetone

  • Sulfur dioxide (SO2)

  • Carbon disulfide (CS2)

  • Hydrogen sulfide (H2S)

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Genetics and Breeding

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Terroir

Overview

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Appellations

Overview

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Terminology

What is a landrace?

A landrace is a domesticated, locally adapted, traditional variety of Cannabis that has developed over time, through adaptation to its natural and cultural environment while being isolated from other populations of the species.

 

Specimens of a landrace tend to be genetically very similar, though much more diverse than members of hybrid, heirloom and IBL populations. Some heirlooms and modern hybrids originate from attempts to make landraces more consistent or stable through selective breeding, however, stabilising a landrace may result in the genetic resource of a landrace being lost through cross and inbreeding.

Landraces are distinct from ancestral wild-type Cannabis. Not all (if any) Cannabis landraces derive from ancient stock largely unmodified by human breeding interests. In a number of cases, domesticated cannabis escaped in sufficient numbers in an area to breed feral populations that, through evolutionary pressure, can form new landraces in only a few centuries.

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In other cases, simple failure to maintain breeding regimens can do the same. For example, selectively bred cultivars can become new landraces when loosely selective reproduction is applied.

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Increasing adoption of and reliance upon modern, purposefully selected cultivars, considered improved – "scientifically bred to be uniform and stable" – has led to a reduction in biodiversity. 

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The majority of the genetic diversity of domesticated species lies in landraces and other traditionally used varieties, they can be considered "reservoirs of genetic resources".

What are the characteristics of a landrace?

General features that characterise a landrace may include:

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  • It is morphologically distinctive and identifiable (i.e., has particular and recognizable characteristics or properties), yet remains "dynamic".

  • It is genetically adapted to, and has a reputation for being able to withstand, the conditions of the local environment, including climate, disease and pests, even cultural practices.

  • It is not the product of formal (governmental, organizational, or private) breeding programs, and may lack systematic selection, development and improvement by breeders.

  • It is maintained and fostered less deliberately than modern hybrids, with its genetic isolation principally a matter of geography.

  • It has a historical origin in a specific geographic area, will usually have its own local name(s) and will often be classified according to intended purpose.

  • Landraces tend to show high stability of yield, even under adverse conditions, but a moderate yield level, even under carefully managed conditions.

  • At the level of genetic testing, its heredity will show a degree of integrity, but still some genetic heterogeneity (i.e. genetic diversity).

 

Not every source on the topic enumerates each of these criteria, and they may be weighted differently depending on a given source's focus (e.g., governmental regulation, biological sciences, agribusiness, anthropology and culture, environmental conservation, pet keeping and breeding, etc.). Additionally, not all cultivars agreed to be landraces exhibit all possible landrace characteristics.

What does the word ‘landrace’ mean?

The word landrace literally means 'country-breed' (German: Landrasse) and close cognates of it are found in various Germanic languages. Equivalents are found in several other languages, notably ‘Bheldia’ as a term to describe Cannabis landraces from the Maghreb..

 

The term was first defined (in German) by Kurt von Rümker in 1908, and more clearly described (in Dutch) in 1909 by U. J. Mansholt, who wrote that landraces have better "stability of their characteristics" and "resistance capacity to tolerate adverse influences" but lower production capacity than cultivars, and are apt to change genetically when moved to another environment. H. Kiessling added in 1912 that a landrace is a mixture of phenotypic forms despite relative outward uniformity, and a great adaptability to its natural and human environment. The word entered non-academic English in the early 1930s, by way of the Danish Landrace pig, a particular breed of lop-eared swine.

 

A landrace native to, or produced for a long time (e.g. 100 years or longer) within the agricultural system in which it is found is referred to as an autochthonous landrace, while an introduced one is termed an allochthonous landrace. 

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