# Serration

> The saw-toothed edge of a cannabis leaflet, with teeth pointing toward the leaflet tip.

- Canonical: https://genetixbay.com/knowledge/glossary/serration.html
- Also written: serrated edge, serrations, leaf teeth, toothed margin
- Glossary category: Plant biology
- 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"

Serration is the toothed margin of a leaf. Cannabis leaflets are serrate: a regular row of sharp teeth along each edge, angled toward the tip. The degree of serration (fine, coarse, double) varies by genotype and is one of the visible leaf traits used in plant descriptions and variety test guidelines.

## In practice

Serration is a quick identifier. The [first true leaves](https://genetixbay.com/knowledge/glossary/true-leaves.md) of a seedling are serrated; the cotyledons are not. That is how growers tell them apart at a glance. Adult leaflets keep their teeth unless something distorts the leaf.

Changes along the margin are diagnostic. [Burnt tips](https://genetixbay.com/knowledge/glossary/nutrient-burn.md) that creep inward point to excess salts or high [EC](https://genetixbay.com/knowledge/glossary/ec.md); rust-coloured spotting along the edges often points to potassium or calcium issues, after [pH](https://genetixbay.com/knowledge/glossary/ph.md) and [root zone](https://genetixbay.com/knowledge/glossary/root-zone.md) are ruled out; tightly curled, twisted margins with odd serration on new growth can indicate [broad mites](https://genetixbay.com/knowledge/glossary/broad-mite.md) or herbicide drift.

Some leaf-shape mutants, such as smooth-edged "duckfoot" types, lose normal leaflet separation and serration. These are genetic variants, not [deficiencies](https://genetixbay.com/knowledge/glossary/nutrient-deficiency.md).

## Don't confuse with

- **Leaflet**: the blade that carries the serrated edge.
- **Clawing**: leaflet tips curling down, a separate symptom.
- **Trichomes**: hair-like outgrowths on the surface, not the edge.

## Related terms

[Leaflet](https://genetixbay.com/knowledge/glossary/leaflet.md), [True leaves](https://genetixbay.com/knowledge/glossary/true-leaves.md), [Fan leaf](https://genetixbay.com/knowledge/glossary/fan-leaf.md)

## Read more

- [Cannabis plant biology: the parts and what they do](https://genetixbay.com/knowledge/basics/cannabis-plant-biology.md)

## Sources

1. UPOV. 2023. Test guidelines for hemp (Cannabis sativa L.), TG/276/1. https://www.upov.int/edocs/tgdocs/en/tg276_01.pdf