Short answer. Because names travel more easily than plants. And the "indica", "sativa" or "hybrid" tag beside the name is no better: it's one species, nearly everything sold is a hybrid, and the tag doesn't predict chemistry or effects (see indica, sativa and ruderalis). Studies sampling retail cannabis found genetic outliers within most same-named strains [2], genome-wide similarity between "indica" and "sativa" labelled samples [3], and labels that only loosely track chemistry [4]. Some names are consistent; many are not. Trust sources and evidence, not names.
What the studies found
| Study | What they did | Key finding | Evidence |
|---|---|---|---|
| Sawler et al. 2015 [1] | 14,031 SNPs in 81 marijuana and 43 hemp samples | Genetic structure only moderately correlated with reported sativa/indica ancestry; strain names often did not reflect a meaningful genetic identity | Supported |
| Schwabe & McGlaughlin 2019 [2] | 10 microsatellites; same-named strains from dispensaries in three US states | Most strains had at least one genetic outlier; after removing outliers many strains were fairly stable; type labels did not match genetic groups | Supported (limited sample, 3 states) |
| Watts et al. 2021 [3] | >100,000 SNPs and chemical profiles of hundreds of samples | "Sativa" and "indica" labelled samples were genetically indistinct genome-wide; labels associated with a few terpenes (myrcene, guaiol, β- and γ-eudesmol for "indica"; bergamotene, farnesene for "sativa") linked to terpene synthase gene regions | Supported |
| Smith et al. 2022 [4] | Lab data from 89,923 samples in six US states | Distinct chemotypes exist, but commercial labels don't consistently align with them; some strain names were consistent, others "consistently inconsistent" | Supported |
| Jikomes & Zoorob 2018 [5] | Washington State lab data | Reported THC varied systematically by testing lab | Supported |
| Henry et al. 2020 [6] | 22-SNP assay on 420 accessions from licensed producers | Clear population structure linked to chemotype; genetic identity relates to chemical composition | Supported |
| Zhang et al. 2021 [7] | Hemp cultivars from different suppliers | Same-named cultivars from different sources flowered differently | Supported (hemp) |
Why it happens
- Seed vs clone. A name sold as seed is a population of different genotypes; a clone name is one genotype. Both get the same name.
- Renaming and borrowing. Cuts renamed to sound new; popular names reused on unrelated genetics.
- Segregation. Even honest seed lines vary, especially F1s of heterozygous clones and F2s.
- Mix-ups. Labels lost in nurseries, mother rooms and supply chains.
- Marketing labels. "Indica" and "sativa" on menus mostly track expected effect and aroma, not ancestry [3].
- Lab variation. Potency differences partly reflect the lab, not the plant [5]. Flower labelled above ~35 % total cannabinoids isn't credible; see buyer beware.
What this means for you
| You want to... | Do this |
|---|---|
| Buy seed you can trust | Prefer lines with a GenetixBay record at L2+ from a certified breeder, batch records and grower journals |
| Trust a clone | Ask for documented chain of custody and, for important cuts, a genotype comparison with a reference sample |
| Compare two "same" strains | Compare sources and, if needed, DNA; don't rely on name or THC number |
| Choose by effect | Use chemistry (cannabinoids and dominant terpenes) as a rough guide; effects are reported, not promised |
How GenetixBay handles names
- A GB-GEN is "this name as released by this breeder or source". Two lines with the same name from different sources are separate records linked as
shares_name, never merged on name alone. - Aliases and misspellings are recorded with sources.
- Every lineage claim carries an evidence level (L0-L4). See documenting lineage evidence.
Common mistakes
- "It says Blue Dream, so it's the Blue Dream." Maybe. Check the source.
- Treating "indica = sedating, sativa = energising" as genetics. It's marketing shorthand loosely tied to a few terpenes (Contested as an effect predictor) [3].
- Dismissing all names. Some are consistent, and a well-documented line is meaningful.
Evidence
- Within-name genetic inconsistency: Supported by multiple independent studies [1][2].
- Indica/sativa labels not reflecting genome-wide ancestry: Supported [1][3].
- Weak alignment between labels and chemotype: Supported [4].
- Lab effects on potency: Supported [5].
A SNP (single nucleotide polymorphism) is a position in the DNA where plants differ by one base letter; thousands of them form the markers used in cannabis genotyping.Hemp is cannabis grown for fibre, seed or other uses and, in many laws, defined as Cannabis sativa with no more than 0.3% THC by dry weight.Terpenes are volatile hydrocarbon compounds built from five-carbon isoprene units; in cannabis they are made in the trichome heads and are a major part of aroma and flavour.A gene is a stretch of DNA that carries the instructions for one functional product, usually a protein such as an enzyme, and is the basic unit of inheritance.A chemotype is a plant's chemical phenotype, in cannabis usually its dominant cannabinoid class: THC-dominant (I), mixed (II), CBD-dominant (III), CBG-dominant (IV) or cannabinoid-free (V).THC (Δ9-tetrahydrocannabinol) is the neutral, decarboxylated cannabinoid mainly responsible for cannabis's reported intoxicating effects; the living plant makes it almost entirely as THCA.An accession is a distinct sample of plant material (seed, tissue or cuttings) entered into a collection or gene bank under its own ID with records of origin.A licensed producer is a business authorised by a regulator to grow, process or sell cannabis commercially, subject to security, tracking, testing and labelling rules.The genotype is the set of alleles a plant actually carries, either at one locus or across its whole genome, as opposed to the traits you can see.Segregation is the separation of a plant's two alleles at each locus into different gametes, so offspring of a heterozygous parent vary in which allele they get.F1 is the first generation of offspring from crossing two parents; if the parents are inbred and different, F1 plants are uniform and often show hybrid vigour.A plant is heterozygous at a locus when it carries two different alleles there (Aa), so its offspring can inherit either one and segregate.F2 is the second filial generation, made by crossing or selfing F1 plants; it shows the widest segregation, bringing back hidden recessives and new combinations.Total cannabinoids is the sum of all cannabinoids a lab measured in a sample, usually reported in % w/w, with acid forms either summed raw or decarboxylation-adjusted.GenetixBay evidence levels rate lineage claims from L0 (unverified) through L1 community reported, L2 breeder reported and L3 documented to L4 lab-confirmed.A cannabinoid is any compound that binds the body's cannabinoid receptors or shares the typical cannabis terpenophenolic structure; the plant-made ones are phytocannabinoids such as THCA and CBDA.
