This is the second in a series of whitepapers by the editorial board. Smoke Reports is a small San Francisco company working hard to improve the relationship between cannabis and human beings through education, outreach and technology. Our editorial whitepapers are intended to express our views on cannabis and the cannabis industry. They are meant to engage a discussion among all members of the cannabis community – growers, manufacturers, dispensaries, retailers, patients and consumers. We encourage your comments and feedback. You can also read our first whitepaper on the language of cannabis.

Beyond Indica and Sativa: A Greater Understanding of Cannabis Genetics

An editorial whitepaper from


The cannabis industry references their products into two broad classifications based on efficacy: sativa and indica. This classification is widely believed to be science-based and is often validated by observable plant characteristics. There is no scientific consensus of the taxonomy and no correlation between plant appearance and physiological response. Essentially, all drug-type cannabis is a genetic mix of Cannabis sativa and Cannabis indica, resulting from recent hybridized breeding.

Cannabis strain differences are the result of plant evolution closely tied to geographic origin. Although classifying cannabis as sativa or indica may give broad description of an individual strain’s efficacy, a more precise description of efficacy is based on the geographic evolution of landrace characteristics. Cannabis results in a variety of responses, and should not be oversimplified into sedatives and stimulants.

Cannabis deserves a better conversation.” –

Referring to cannabis as sativa or indica is only the beginning of a better conversation.”


Smoke Reports is a small San Francisco company working hard to improve the relationship between cannabis and human beings through education, outreach and technology.

The purpose of this editorial whitepaper is to put forth a discussion topic promoting that relationship – the language that we as an industry use when referring to our products. It’s the second in a series of three editorial whitepapers dealing with modern cannabis language. The editorial board at observes that the language used to differentiate cannabis strains is being confused with actual science. We believe that representing cannabis as “indica” and “sativa” as scientific is a disservice to cannabis consumers because it is inaccurate and divert people from what is potentially the best cannabis for them.

Cannabis indica and Cannabis sativa are biological classifications. Industry observers pronounce that the cannabis that relaxes you is “indica” and the cannabis that energizes you is “sativa” – and further infer that species identification makes it so. Here at, we believe that cannabis deserves a better conversation. That better conversation requires the divorce of anecdotal observations from scientific fact. Every resin-producing cannabis strain is derived from Cannabis indica, although a major boom in breeding has created hybrid strains, showing genetic qualities of both Cannabis indica and Cannabis sativa. does NOT believe in the ending of the practice of referring to cannabis as indica, sativa or hybrid. Our website visitors and our customers (seed companies, cultivators, producers, manufacturers and dispensaries/retailers) rely on these terms to broadly describe the common effects of their cannabis products. Our hope is that through greater communal understanding, the cannabis industry and community can recognize the depth involved with cannabis genetics, and appreciate that indica and sativa does not necessarily mean everyone will feel the same sedative or stimulating effects.

Discussion: The Biological Classification of Cannabis indica and Cannabis sativa

This discussion draws from the definitive text: Cannabis – Evolution and Ethnobotany by Robert C. Clarke and Mark D. Merlin.[1]

Clarke and Merlin, Cannabis: Evolution and Ethnobotany

Cannabis – Evolution and Ethnobotany by Robert C. Clarke and Mark D. Merlin

Although innumerable articles may be found with descriptions of Cannabis sativa and Cannabis indica, few have any real scientific basis. Popular pronouncements explain that the sativa plant is tall and thin-leafed whereas the indica plant is short and broad-leafed. Similarly, sativa provides one type of physiological effect, indica another. What does science actually say?

Clarke and Merlin divide modern cannabis into four origin categories and identify the genus Cannabis species sativa and indica as belonging in all four categories. (They describe a total of ten origin species, six of which are not found modernly). The four origin species giving rise to modern cannabis are:

  • Broad-Leaf Hemp
  • Broad-Leaf Drug
  • Narrow-Leaf Hemp
  • Narrow-Leaf Drug [2]

According to Clarke and Merlin, “Narrow-leaf hemp, C. sativa L., has been characterized by its tall stature, less developed branching . . . and spicy or sweet aroma. Narrow-leaf drug varieties of C. indica subspecies indica . . . secrete resins of high cannabinoid content, predominately psychoactive THC, while [narrow-leaf hemp] fiber varieties of C. sativa secrete resin that is much lower in total cannabinoids, and particularly low in THC[3]. . . Largely owing to their ability to synthesize THC, the three cultivated C. indica subspecies attracted the attention of humans who broadened their ranges around the world.”[4]

First conclusion from Clarke and Merlin’s work: The four origin species are a mixture of Cannabis sativa and Cannabis indica. Second, if there is a high concentration of resin on the flowers, the biologic classification should be Cannabis indica. Third conclusion: Narrow-leaf plants are either of the Cannabis sativa or Cannabis indica species. Therefore, categorizing cannabis as sativa or indica according to physiological efficacy is not science-based, and categorizing the cannabis plant into sativa or indica by observable plant characteristics is equally unscientific.

To further dilute the distinction between Cannabis sativa and Cannabis indica, “By the early to mid-1980s, the vast majority of all sinsemilla[5] for sale in North America had probably received some portion of its genome from the [Broad-Leaf Drug] gene pool. “[6] Therefore, there is no single genome origin for modern cannabis. The cannabis found today is a cross-breed of the four origin species, each of which are a mix of Cannabis sativa and Cannabis indica species.


Cannabis Leaf Sketches

As a final note, “Genus Cannabis has been variously characterized by modern taxonomists . . . some favored lumping all Cannabis taxa together into the single species [Cannabis] sativa, circumscribing two subspecies (hemp and drug) . . . Others split Cannabis into three species [Cannabis] sativa, [Cannabis] indica, and [Cannabis] ruderalis, each species circumscribing its own varieties . . .”[7] Hence, although you can read factual information describing a difference between Cannabis sativa and Cannabis indica, the scientific community is still in disagreement about whether there are two biologic cannabis species and/or whether there is a third. Clearly, science says that popular consumer differences between “sativa” and “indica” are not the same as the biologic classification of Cannabis sativa and Cannabis indica.

Landraces: Cannabinoid Ratios and Geography

According to Clarke and Merlin, cannabinoids and terpenoids evolved within each cannabis strain in specific locations in reaction to weather, light duration, soil condition and availability of water. Also present: the influence of purposeful breeding to create desired plant qualities. Clarke and Merlin identify eleven geographical regions, each with unique cannabinoid chemotypes: [8]

  • North America
  • Western Europe
  • Eastern Europe
  • Central America and the Caribbean
  • South America
  • Middle East
  • East Asia
  • Indian Subcontinent
  • Southeast Asia
  • Equatorial Africa
  • South and East Africa

One can therefore conclude that the mix of the naturally occurring compounds within any specific cannabis strain is highly reflective of its geographic origin. The set of characteristics that is indigenous to a particular region is known as a landrace strain.

Cannabis Landraces

Cannabis Landraces

The Effective Compounds in Cannabis and Individual Efficacy

Cannabinoids are chemical compounds that act on receptors in the endocannabinoid system. There are currently 85 known cannabinoids, all unique molecules that cause a variety of effects on the endocannabinoid system

  • THC (tetrahydrocannabinol): produces psychoactive effects by binding to CB1 receptors in the brain. Binds to both CB1 and CB2 receptors. Mimics the endocannabinoid anandamide.
  • CBD (cannabidiol): non-psychoactive. CBD has little affinity for CB1 and CB2 receptors, but favors CB2 receptors. CBD has been shown to suppress the effects of THC by blocking uptake of THC at cannabinoid receptors
  • CBG (cannabigerol): non-psychoactive, CB1 receptor antagonist
  • CBC (cannabichromene): non-psychoactive, does not effect receptors
  • CBN (cannabinol): product of THC degradation, weak psychoactive effect, content increases when the plant is exposed to light and air
  • THCV (tetrahydrocannabivarin): Reduces psychoactive effects of THC by binding to CB1 receptors. Noted in certain strains of cannabis from central Asia and southern Africa
  • CBL (cannabicyclol)
  • CBDV (cannabidivarin)
  • CBCV (cannabichromevarin)
  • CBGV (cannabigerovarin)
  • CBGM (cannabigerol monomethyl ether)

– From the Smoke Reports FAQ [9]

A recent article in the Journal of the American Medical Association stated, “These cannabinoids have individual, interactive, and even entourage effects (effects of a compound that are only appreciable in the presence of other compounds) that are not fully understood and that contribute to the net effect of marijuana . . . Given the variable composition, patients will have to experiment with different strains and doses to achieve the desired effects . . .” [10] Therefore, whether you feel a heavy high from indica or feel a vigorous high from sativa is dependent upon the THC in combination with the entourage effect of the cannabinoids.

Individual physiology further determines psychoactive effects. The endocannabinoid system (ECS) is a group of naturally-occurring molecules (endocannabinoids) and their receptors in the brain and elsewhere throughout the human nervous system. Each individual’s ECS-receptor system is different. Therefore each strain of cannabis will have a different effect dependent upon the individual’s ECS and the plant’s chemotype (the ratio of cannabinoids present). Classifying cannabis by its psychoactive effect is not as simple as choosing among two cannabis categories.


Broadly categorizing cannabis products into indica or sativa (or hybrid) is not science-based and not sufficiently descriptive. Cannabis deserves a better conversation. As each landrace strain offers a unique proportion of THC and other cannabinoids, and as each individual’s endocannabinoid receptor system is different, we believe efficacy is more closely related to a plant’s geographic origin.

Found in strain descriptions are landrace maps which may be used to identify the qualitative differences in cannabis strains based on science. Our proprietary recommendation results rely heavily on categorization by the more complex identification of landrace, providing a better opportunity to categorize the similar qualitative properties in cannabis strains that affect each individual person.


Budtender Suggesting Strains to a Cannabis Patient (source)


Laboratory scientist at CW Analytical of California say, “There is a great deal of confusion in the current medical cannabis industry with regards to the efficacy of various strains/forms of cannabis. Attributes ascribed to strains such as “indica” and “sativa” . . . have no proven scientific basis. All of this information is anecdotal.” believes these terms are fine as long as we recognize that it is consumer language, and not verified science. Writings purporting to convey this as scientific information are misinformed.

Science tells us that the subtle differences in the psychoactive experience are found in the mix of THC and other cannabinoid components – the entourage effect. Cannabis strains evolved with a unique mix of cannabinoids by geographic origin. Therefore, when psychoactive effects are categorized for an individual consumer, we believe landrace is the best identifier. Smoke Reports says, “Cannabis deserves a better conversation.”We believe that classifying cannabis into an indica category or a sativa category is only the beginning of that conversation, like asking if you prefer red or white wine. We pursue a classification system based on genetic landrace groupings, a more accurate examination of cultivars.

Cannabis and hemp are legitimate agricultural products with legitimate industrial, medical and social purpose. Our language as a community and industry should reflect the legitimacy of cannabis. We urge all to repeat the mantra, “Classifying cannabis into sativa and indica is only the beginning of a better conversation.”


[1] Clarke, Robert C., and Mark D. Merlin. Cannabis – Evolution and Ethnobotany. Berkeley: University of California Press, 2013. Print.
[2] Ibid, Table 1
[3] Ibid, p. 314
[4] Ibid, p. 368
[5] A growing technique separating male plants from female flowering plants during cultivation.
[6] Clarke and Merlin, Ibid, p. 302
[7] Ibid, p. 314
[8] Ibid, p. 54-55
[10] Journal of the American Medical Association, June 23/30, 2015 Volume 313, Number 24 p.2431

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