How Cultivar Profiles Work: Sources, Batches and Uncertainty

Strain or cultivar?

In everyday talk, a named type of cannabis is called a "strain." Researchers often use the word cultivar, meaning a cultivated variety of a plant. Scientific papers on cannabis use both words, and one study describes distinct varieties or cultivars as having each been cultivated to express certain traits. [1] This library uses "cultivar" and mentions "strain" because that is the word most people search for. For the wider picture see Cultivars, Chemotypes and Strain Names.

A cultivar profile here is information only. It does not tell anyone what to use, how much, or what to expect.

Six kinds of information, kept apart

A name on a package mixes several different kinds of statement. Each profile in the Cannabis Cultivar Directory keeps them in separate boxes, because they have very different levels of proof.

Why a name does not prove genetics

In a genetic study of 81 drug-type and 43 hemp samples, researchers found that in 6 of 17 comparisons, samples were more similar to samples with different names than to samples with identical names. They concluded that the genetic identity of a strain cannot be reliably inferred from its name or reported ancestry. [2]

Another study looked at 30 named strains bought from dispensaries and donors in three US states (122 samples). It found that most strains had at least one genetic outlier, although after removing obvious outliers many strains showed considerable genetic stability. [3] The same paper noted that some strains are reportedly propagated by cloning, which should leave little genetic variation, while others are grown from seed. [3]

So a name may point to a fairly consistent plant, a loose family of plants, or a marketing term. Which one it is differs from name to name.

Why chemistry differs between batches

Even a genetically consistent cultivar can test differently. A large analysis of commercial samples from six US states found that labels did not consistently line up with measured chemistry. It also found that many strain names were more consistent from product to product than chance would predict, but with a wide range of consistency between names. [1] The authors said they could not separate genetic effects from growing conditions in that dataset. [1]

Testing adds another layer. An analysis of Washington State seed-to-sale records found systematic differences between laboratories in the cannabinoid levels they reported, and those differences could not be explained by producer, product type or strain name. [4] In plain terms, the same product can get a different number depending on who tests it and how.

This is why a profile may show a lab result only when we can read the source, and then always with the batch, laboratory, date, method and units. If we cannot, the profile says that composition varies and verified batch data was not available. We never print a "typical" percentage. To learn how to read a lab report yourself, see How to Read a Cannabis Certificate of Analysis and Laboratory Variability, Batch Numbers and Test Dates.

Confidence labels used in profiles

• Verified: a source we read confirms the statement directly.
• Reported: a breeder, database or article says so, and we could not check it independently.
• Disputed: sources disagree.
• Genetic evidence: a genetic study supports a relationship.
• Unknown: we looked and could not find a readable source.

The note "Proper evidence not found" means we searched and found no usable study for that question. It does not mean the answer is no.

Indica, sativa and hybrid labels

Retail labels are one of the six kinds of information, and a weak one. One genome-wide study found that sativa-labeled and indica-labeled samples were genetically indistinct overall, with the labels linked instead to differences in a few aroma compounds. [5] The authors of the six-state chemistry study wrote that the indica, hybrid and sativa wording does not reliably distinguish samples by chemical content. [1] See Why Indica and Sativa Labels Do Not Reliably Predict Individual Effects.

Safety note

Cannabis can cause impairment, anxiety, a racing heart and other adverse effects, and a product that tests differently from the last one can feel different. Nothing in a cultivar profile predicts how a person will respond. For risks and when to seek help, read Cannabis Adverse Effects, Cannabis Use Disorder and When to Seek Help. If a child has swallowed any cannabis product, call US Poison Help at 1-800-222-1222 or 911 in an emergency.