History of Cannabis TaxonomyHow is Cannabis best categorized and named? Are there really multiple species, or just one? We compiled some basic information about the taxonomy of Cannabis into an interactive timeline for use as a learning tool. Our information was largely sourced from Robert Clarke and Mark Merlin's Cannabis: Evolution and Ethnobotany (2013).
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"There are biochemically distinct strains of Cannabis, but the sativa/indica distinction as commonly applied in the lay literature is total nonsense and an exercise in futility."
- Ethan Russo, MD
From: The Cannabis sativa versus Cannabis indica Debate: An Interview with Ethan Russo, MD
from Cannabis and Cannabinoid Research Journal Volume 1, Number 1
from Cannabis and Cannabinoid Research Journal Volume 1, Number 1
What is a Strain?
Technically speaking, a "strain" is not a recognized taxonomical rank in botany. Rather, "strains" represent somewhat arbitrary groups of plants that are similar according to particular traits - such as shape, size, chemical profile, or genetic profile. In breeding, the term "strain" is often used to represent the offspring of a modified plant.
The use of strain names is muddied by the fact that strain names are often given to offspring that are propagated either sexually, by seed, or asexually, through cloning. Although clones may be genetically similar to their parent, seed propagated plants are less so. Sexual propagation introduces genetic variation. Because seed plants often inherit the strain name of their parent, a single strain's lineage may consist of plants that exhibit very different shapes, sizes, and chemical profiles compared to the parent. Researchers attempting to study the history of Cannabis evolution have revealed that strain names are very unreliable in predicting genetic lineage.
So what does this mean for consumers? Take less stock in strain names and focus on the chemical profile of each specific product. Keep track of CBD:THC ratios and dominant terpenes of products that you find beneficial.
The use of strain names is muddied by the fact that strain names are often given to offspring that are propagated either sexually, by seed, or asexually, through cloning. Although clones may be genetically similar to their parent, seed propagated plants are less so. Sexual propagation introduces genetic variation. Because seed plants often inherit the strain name of their parent, a single strain's lineage may consist of plants that exhibit very different shapes, sizes, and chemical profiles compared to the parent. Researchers attempting to study the history of Cannabis evolution have revealed that strain names are very unreliable in predicting genetic lineage.
So what does this mean for consumers? Take less stock in strain names and focus on the chemical profile of each specific product. Keep track of CBD:THC ratios and dominant terpenes of products that you find beneficial.
Modern Cannabis Taxonomy
Researchers have long disagreed about how Cannabis should be categorized and named, but some consensus is beginning to be reached as we better understand the chemistry, genetics, morphologies, and breeding behaviors of different Cannabis cultivars. What researchers generally agree on today is that all THC-dominant varieties of Cannabis, or "drug type" varieties, belong to a single gene pool and species. Researchers still disagree whether any unique gene pools represent distinct species or subspecies.
A modern taxonomic model for Cannabis proposed by Robert Clarke and Mark Merlin is as follows:
Researcher Karl Hillig discovered in the early 2000s that there appear to be two distinct gene pools of Cannabis with all drug varieties and some hemp varieties encompassing one gene pool, and then a particular set of European and Asian hemp varieties encompassing the second gene pool. A current debate among researchers is whether these gene pools represent separate species or subspecies. In addition, not all taxonomists agree with Clarke and Merlin's proposed model, so the debate about the taxonomy of Cannabis still rages on to this day.
Currently the Integrated Taxonomic Information System recognizes a single Cannabis species, Cannabis sativa.
A modern taxonomic model for Cannabis proposed by Robert Clarke and Mark Merlin is as follows:
- Single "Putative Ancestor (PA)"
- A proto-sativa "Putative Hemp Ancestor (PHA)"
- Narrow leaf hemp ancestor
- Narrow leaf hemp cultivars - Cannabis sativa ssp. sativa
- Narrow leaf hemp ancestor
- proto-indica "Putative Drug Ancestor (PDA)"
- Narrow leaf drug ancestor
- Narrow leaf drug cultivars - Cannabis indica ssp. indica
- Broad leaf hemp cultivars - Cannabis indica ssp. chinensis
- Broad leaf drug ancestor
- Broad leaf drug cultivars - Cannabis indica ssp. afghanica
- Narrow leaf drug ancestor
- A proto-sativa "Putative Hemp Ancestor (PHA)"
Researcher Karl Hillig discovered in the early 2000s that there appear to be two distinct gene pools of Cannabis with all drug varieties and some hemp varieties encompassing one gene pool, and then a particular set of European and Asian hemp varieties encompassing the second gene pool. A current debate among researchers is whether these gene pools represent separate species or subspecies. In addition, not all taxonomists agree with Clarke and Merlin's proposed model, so the debate about the taxonomy of Cannabis still rages on to this day.
Currently the Integrated Taxonomic Information System recognizes a single Cannabis species, Cannabis sativa.
Additional Resources
John McPartland's Suggested Revised Cannabis Nomenclature
Cannabis: Evolution and Ethnobotany by Robert Clarke and Mark Merlin
Medicinal Genomics' Kannapedia Database of Cannabis Genetics
Phylos Galaxy of Cannabis DNA
The Genetic Structure of Marijuana and Hemp by Sawler et al
The Cannabis sativa versus Cannabis indica Debate: An Interview with Ethan Russo, MD
The Cannabis Taxonomy Debate: Where Do Indica and Sativa Classifications Come From? via Leafly.com
Cannabis: Evolution and Ethnobotany by Robert Clarke and Mark Merlin
Medicinal Genomics' Kannapedia Database of Cannabis Genetics
Phylos Galaxy of Cannabis DNA
The Genetic Structure of Marijuana and Hemp by Sawler et al
The Cannabis sativa versus Cannabis indica Debate: An Interview with Ethan Russo, MD
The Cannabis Taxonomy Debate: Where Do Indica and Sativa Classifications Come From? via Leafly.com
