Resources & Tools

Grow Basics
Go Back

The Ethos Of Plant Names: Genetics Nomenclature

By Colin Gordon and Ben Owens

Even for the most experienced growers, the wide variety of acronyms, abbreviations, and nomenclature within the cannabis genetics industry can be confusing because it lack specificity. The large spectrum of terms can be hard to parse and hard to keep up with, especially if you’re new to growing or getting back into it after an extended hiatus. Creating a consistent language is imperative for progress in any advancing field, especially genetics. ETHOS uses a specific nomenclature to reference all of our cultivars. For that reason, we’ve decided to clarify our terminology and nomenclature.

ETHOS Nomenclature
ETHOS was founded on the principle that the current landscape of genetics could be improved through standardization. For that reason, we have stuck to a very specific, consistent methodology for naming our genetics. Generally speaking, letters indicate the process by which the genetics were produced and the number indicates the generation and/or variance expressed by those genetics.

Here’s how ETHOS refers to its various offerings:

S1 - “Selfed” First Generation
An S1 is the result of a plant being crossed with itself, without any other plant being involved in the procreation. There are a variety of ways to induce this effect in a plant, but the general understanding is that any plant with an S1 label has only one female parent’s set of genes. The female parent pollinates herself or a clone of herself. This term is only used when a plant is crossed into herself. Any back cross or hybrid will have a different term. Often, the term “S1" is misused in a broad stroke manner to describe any female seed which is incorrect. S1’s can only be those female seeds produced by a single parent.

F1 - Filial (Offspring) First Generation
By definition, an F1 is the result of the initial cross between two unrelated and stable cultivars. For example, Parent One (P1) and Parent Two (P2) could be crossed to result in Plant A, an F1 offspring. This is the first generation resulting from the cross of these cultivars.

BX1 - Back Cross First Generation
A back-crossed offering involves taking a filial and crossing it back into one of its original parents. Using our example from before, P1 crossed with P2 yields A, our F1. By crossing A with either P1 or P2, you produce a back-cross (P1A or P1B), either cross resulting in a first generation back-cross (BX1).

RBX (Reverse Back-cross)
A reverse back-cross is a back-cross that involves a female pollen donor.

F2, F3, F4, F5 and Successive Filial Generations
What's the difference between an F2 and an F5? F2 is when two filial from an F1 are crossed with one another. The goal of this continued breeding within cultivars is to stabilize the expressions of the plants, narrowing the variances to a handful instead of hundreds. If you continue this process, the next round is F3 and so on. (two filial from an F2 are crossed, resulting in an F3). In modern cannabis, variety homogenization starts to set in by the F3 stage. F4, F5 and beyond will likely be the most stable expressions of that particular variance.

V1, V2, & V3 - Versions
A “V” indicates a slightly different version of an existing cultivar. As expressions stabilize and versions homogenize, different versions are identified by a V and their respective numeral. A plant with two distinctive versions would be labeled as a V1 or a V2. You typically won’t see a V1 as the first version of the cultivar is its first version, regardless of whether it is an R1 or F1. A V may be used to identify cultivars who have been bred with the goal of an existing cross but using different parents than the original version.

For example:
Mandarin Cookies R1 (V1) = Forum Cut Cookies x Mandarin Sunset
Mandarin Cookies V2 = ETHOS Cookies x Mandarin Sunset (Second Version of Mandarin Cookies)

>> Leaves a void with only the F1 system. And very rare to properly use the term F1 in modern cannabis

Difference of Opinion
Technically, an F1 is a cross of two unrelated parent cultivars. So, in theory, that would mean that each parent would have to be distinctly unrelated to one another, even in its traceable lineage. In classic genetic models, this would look something like Purple Basil x Green Basil. But, given the hybridization of the genetics industry, are there any true F1’s left in cannabis?

Genetic models for classification that exist in current academia are based on 2 qualifications:
• That the parents are unrelated
• That the parents are already stabilized.

This leaves a massive void of accuracy within the F1 system. Very rarely will you see brands and shops properly use the F1 term in modern cannabis.

Less than 5% of the parents used in seed-making are genetically stable, and more than 80% of dispensary cannabis has one parent with some genetic relation to the other, and in more than half of the cases, the parents share significant amounts of genetic relation. So, while we refer to crosses from two unique parents as an F1, can we even predicate our terms and nomenclature on a preexisting construct that fundamentally doesn't apply to this specific space of cannabis breeding?

ETHOS will always be transparent with its labeling and lineage of its genetics. This is how we feel genetics should be labeled. Everyone in this industry has a different approach, and this is ours. If you agree and enjoy the consistency and transparency of our product offerings, we invite you to subscribe to our content and sign up for the only genetics membership you’ll ever need.