# Achene

> The dry, single-seeded fruit of cannabis that growers call a seed; a hard shell (pericarp plus seed coat) encloses one embryo and does not split open.

- Canonical: https://genetixbay.com/knowledge/glossary/achene.html
- Also written: cannabis seed, seed (botanical), achenes, fruit
- Glossary category: Plant biology · 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"

An achene is a small, dry, one-seeded fruit that stays closed at maturity. What growers buy as a cannabis "seed" is botanically an achene: the hard outer [shell](https://genetixbay.com/knowledge/glossary/seed-coat.md) is the fruit wall (pericarp) fused tightly over the true seed coat, with a single embryo and a little endosperm inside. Each develops from one [pollinated](https://genetixbay.com/knowledge/glossary/pollination.md) [pistillate flower](https://genetixbay.com/knowledge/glossary/pistillate-flower.md), wrapped in its [bract](https://genetixbay.com/knowledge/glossary/bract.md).

## In practice

Mature achenes are typically 2-5 mm long, grey to brown, often mottled or "tiger-striped", and they rattle out of the bract when ripe, usually around 4-6 weeks after pollination. Pale, green or soft seeds are usually immature and [germinate](https://genetixbay.com/knowledge/glossary/germination.md) poorly. A breeder checks ripeness by the colour, a firm shell that resists a gentle squeeze, and bracts starting to split.

Storage is about the embryo inside: cool, dark and dry. Seeds kept at low moisture and low temperature hold germination for years (Small & Brookes 2012).

## Don't confuse with

- **Seed coat (testa)**: the thin layer of the true seed, inside the achene shell.
- **Bract**: the leafy sheath that wraps the developing achene, not part of the fruit.
- **Calyx**: the reduced [perianth](https://genetixbay.com/knowledge/glossary/calyx.md) on the ovary; often misused for the bract.

## Related terms

[Seed coat](https://genetixbay.com/knowledge/glossary/seed-coat.md), [Cotyledon](https://genetixbay.com/knowledge/glossary/cotyledon.md), [Radicle](https://genetixbay.com/knowledge/glossary/radicle.md), [Bract](https://genetixbay.com/knowledge/glossary/bract.md)

## Read more

- [Seed viability and storage: keeping cannabis seeds alive](https://genetixbay.com/knowledge/germination/seed-viability-storage.md)
- [Cannabis plant biology: the parts and what they do](https://genetixbay.com/knowledge/basics/cannabis-plant-biology.md)

## Sources

1. Small E. 2015. Evolution and classification of Cannabis sativa (marijuana, hemp) in relation to human utilization. The Botanical Review 81:189-294. https://doi.org/10.1007/s12229-015-9157-3
2. Small E, Brookes B. 2012. Temperature and moisture content for storage maintenance of germination capacity of seeds of industrial hemp, marijuana, and ditchweed forms of Cannabis sativa. Journal of Natural Fibers 9(4):240-255. https://doi.org/10.1080/15440478.2012.737179