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Steep Hill's CLADE Method

Updated: Oct 18, 2022

A little over 100 years ago, you could take your morning, afternoon, or evening stroll to your local apothecary and receive a cannabis prescription for mundane illnesses like a stomach ailment.

What’s more interesting, however, was that your pharmacist would simply have to look at the physical properties of their medicinal cannabis to be then able to prescribe you the appropriate treatment. In other words, way back when, you could distinguish Indica strains (characterized by broader leaves, a shorter, denser build, and general darker color) from Sativa strains (characterized by narrow leaves that were lighter in color and taller or lankier in shape) just by looking at them. Indeed, hybridization processes had yet to proliferate; its rapid expansion in the 1960s in North America, however, would forever alter the consumption of the Cannabis plant for enthusiasts and patients alike.

To make matters more complicated, there has yet to be a clear consensus reached regarding the chemical properties contained in the original Indica and Sativa strains - so how can we determine how far we’ve strayed? And if we can, why should we?

Here’s what we do know: terpenoids (the aromatic chemical compounds responsible for many of the physiological characteristics of your high) and cannabinoids (a subset of terpenoids distinguished by their polyphenol groups) are phytochemicals that are secreted as a stress response to the cannabis plant’s environmental conditions. In this way, it presents the opportunity to determine the effects of a particular strain (in a more scientifically rigorous manner than via consumption and self-report) by analyzing its chemical constituents and associating the overall chemical profile concentrations and ratios with anticipated effects.

The good news is the technology required to do so exists. The bad news is that studying the genetic and chemical content of every strain featured in the U.S. cannabis market would produce vast amounts of data that would require an immense amount of manpower to sift through.

Fortunately, we can rely on cannabis testing lab networks based in the U.S. as a means of sorting and aggregating information to draw insightful conclusions. Now, we‘d like to formally introduce you to a brand new CLADE classification system for cannabis.

To clarify, a CLADE is a term used to describe statistically clustered groupings of items that match certain features and are therefore grouped together; for example, cannabis and roses are both members of a clade called “Angiosperms,” as are all flowering plants. Steep Hill Inc.'s team has verified seven cannabis strain CLADEs or classifications of terpene content - originating from large data sets spanning thousands of samples from a multitude of U.S. states - which allow one to group particular strains that share similar genetic and chemical characteristics into a CLADE. More specifically, this classification is determined by measured properties, including the presence of specific combinations of terpenes. Similar groupings can be assembled using the genes that code for those properties (by sequencing the nucleic acids – DNA and RNA). Essentially, we’re looking at the chemical and genetic composition of cannabis strains to classify plant cultivars in a way that allows the selection of phenotypes (the physical expression of a cannabis plant's genetic blueprint) according to their intended use. In this way, any samples brought into cannabis testing labs following the launch and implementation of this novel classification system (quantifying and classifying based on key terpene concentrations), can then be compared and assigned to one of those seven CLADEs.

What differentiates these CLADEs from one another? For example, derived from a sample of oil concentrate, the profile data in CLADE 2 features different tier groups (labeled s1-s4), which are scores defined by their properties: sedative score, anti-anxiety score, AChEl score, and the antinociceptive pain score. In this way, clusters based on the presence or absence of genes for specific traits (determined by measuring the nucleic acid sequences present) can be used to guide breeders in selecting the breeding pairs most likely to produce the desired compounds or traits, including traits such as resistance to drought or other likely stressors.

Why is this important, revolutionary, mind-blowing, or all-of-the-above? This classification system will transform the way cannabis consumers choose the right strain for them and how the industry tailors its offerings to the needs of its recreational and medicinal end-users. Similarly, this classification system can impact everything from farming techniques to the way dispensaries display their products on their shelves.

According to Don Land, Chief Scientific Consultant at Steep Hill:

For end-users, strains from the same clade will have similar effects on most humans, including medicinally relevant effects. This is due to the “Entourage Effect” introduced by Dr. Ethan Russo over a decade ago. Russo and many others hypothesize that terpenes and perhaps other compounds in cannabis augment and contribute significantly to the effects experienced. Generally, the cannabinoid content of most high-THC cannabis is similar and should lead to similar effects. The differences in effects (such as “sativa-energetic” or “indica-relaxing) are mainly due to the differing terpene content, which is, in turn, determined by the presence and expression of the correct genes.

As a grower, you can use genetic tests to determine which terpene genes are present in any plant for hybridization to produce the flowers that consumers want. One could also choose genetic traits that produce terpenes that repel or kill certain pests known to frequent their farm - this classification system could answer these kinds of questions. As a distributor, you may want to be better informed and thus equipped to guide your customers in choosing the right strain for them. You can say “the nose knows,” but that will only take you so far in choosing a strain that will produce the desired effects you’re looking for.

1Taming THC: potential cannabis synergy and phytocannabinoid-terpenoid entourage effects

Ethan B Russo, Br J Pharmacol. 2011 Aug; 163(7): 1344–1364. doi: 10.1111/j.1476-5381.2011.01238.x

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