# Phenotype

> The phenotype is what a plant visibly and measurably is (shape, colour, smell, chemistry, timing), the result of its genotype acting in a particular environment.

- Canonical: https://genetixbay.com/knowledge/glossary/phenotype.html
- Also written: phenotypes, phenotypic expression, observable traits
- Glossary category: Genetics and breeding · Evidence: Established
- Status: Draft: awaiting expert review · Updated: 2026-10-31
- Licence: CC BY-SA 4.0 (https://creativecommons.org/licenses/by-sa/4.0/), attribute "GenetixBay cannabis glossary"

The phenotype is the set of observable traits of a plant: height, leaf shape, flowering time, aroma, resin, [cannabinoid](https://genetixbay.com/knowledge/glossary/cannabinoid.md) profile, pest resistance. It is produced by the [genotype](https://genetixbay.com/knowledge/glossary/genotype.md) interacting with the environment. Phenotype = genotype + environment + their interaction.

## In practice

Growers say "this [pheno](https://genetixbay.com/knowledge/glossary/pheno.md)" to mean one individual plant out of a seed pack, as in "the third pheno smelled like fuel". Strictly, that plant is a genotype that showed a particular phenotype in that room. Run the same clone under a different light, feed or [pot size](https://genetixbay.com/knowledge/glossary/pot-size.md) and parts of the phenotype shift; the genotype does not.

That is why serious selection means growing candidates side by side, in the same conditions, and ideally repeating the best ones as clones before deciding. A plant that stood out because it sat in the hot spot has a good phenotype but may not have a good genotype.

## Don't confuse with

- **Genotype**: the DNA. The phenotype is what you see from it.
- **Pheno (slang)**: shorthand for one [seedling](https://genetixbay.com/knowledge/glossary/seedling.md) or selection; same root, looser use.
- **Chemotype**: the chemical part of the phenotype.

## Myth check

"Indica phenotype" and "sativa phenotype" describe plant shape at most (broad or narrow [leaflets](https://genetixbay.com/knowledge/glossary/leaflet.md), structure, flowering time). They do not predict chemistry or effect (Watts et al. 2021). See [indica, sativa and ruderalis](https://genetixbay.com/knowledge/genetics-history/indica-sativa-ruderalis.md).

## Related terms

[Genotype](https://genetixbay.com/knowledge/glossary/genotype.md), [Chemotype](https://genetixbay.com/knowledge/glossary/chemotype.md), [Pheno hunt](https://genetixbay.com/knowledge/glossary/pheno-hunt.md), [Genotype by environment interaction](https://genetixbay.com/knowledge/glossary/genotype-by-environment.md), [Heritability](https://genetixbay.com/knowledge/glossary/heritability.md)

## Read more

- [Selection and pheno hunting: sample sizes and scoring rubrics](https://genetixbay.com/knowledge/breeding/selection-pheno-hunting.md)
- [Quantitative traits and heritability: why most good traits are hard to fix](https://genetixbay.com/knowledge/breeding/quantitative-traits-heritability.md)

## Sources

1. Falconer DS, Mackay TFC. 1996. Introduction to Quantitative Genetics, 4th edition. Longman, Harlow. ISBN 978-0-582-24302-6
2. Watts S, McElroy M, Migicovsky Z, Maassen H, van Velzen R, Myles S. 2021. Cannabis labelling is associated with genetic variation in terpene synthase genes. Nature Plants 7:1330-1334. https://doi.org/10.1038/s41477-021-01003-y