# Dioecious

> Having male and female flowers on separate individual plants; drug-type cannabis is naturally dioecious with an XY sex-chromosome system.

- Canonical: https://genetixbay.com/knowledge/glossary/dioecious.html
- Also written: dioecy, dioecism, separate sexes, two-house plant
- 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"

A dioecious species has separate male and female individuals: each plant carries only staminate (male) or only pistillate (female) flowers. Cannabis is naturally dioecious. Females are XX and males XY, with [sex chromosomes](https://genetixbay.com/knowledge/glossary/xy-sex-determination.md) confirmed by cytogenetics and genome studies (Divashuk et al. 2014; Prentout et al. 2020). Seed populations normally come out roughly half male, half female.

## In practice

Dioecy is why growers sex plants and why seedless flower is possible: remove the males, keep the females unpollinated. It is also why regular seed matters for breeders. Every true cross needs a male, which is why GenetixBay encourages keeping and documenting good males in [the Stud Book](https://genetixbay.com/knowledge/glossary/stud-book.md).

[Feminised seed](https://genetixbay.com/knowledge/glossary/feminised-seed.md) is made by inducing pollen on a female; the offspring are XX and almost all female.

## Don't confuse with

- **Monoecious**: male and [female flowers](https://genetixbay.com/knowledge/glossary/pistillate-flower.md) on the same plant, as in some bred [hemp cultivars](https://genetixbay.com/knowledge/glossary/hemp.md).
- **Hermaphrodite (intersex)**: an abnormal dioecious individual showing both sexes.
- **Feminised**: a seed-production method, not a change to the species' biology.

## Myth check

GenetixBay position: drug-type cannabis has been recorded as dioecious and stable throughout history. [Herm-prone](https://genetixbay.com/knowledge/glossary/herm-prone.md) lines are mainly the result of breeder error (repeated selfing, careless feminising, unstable "[pollen chucker](https://genetixbay.com/knowledge/glossary/pollen-chucker.md)" releases), not a natural tendency. Stress reveals susceptible genetics; it doesn't make [intersex](https://genetixbay.com/knowledge/glossary/hermaphrodite.md) normal. See [Mythbusters](https://genetixbay.com/knowledge/mythbusters.md).

## Related terms

[Monoecious](https://genetixbay.com/knowledge/glossary/monoecious.md), [Hermaphrodite](https://genetixbay.com/knowledge/glossary/hermaphrodite.md), [Staminate flower](https://genetixbay.com/knowledge/glossary/staminate-flower.md), [Pistillate flower](https://genetixbay.com/knowledge/glossary/pistillate-flower.md)

## Read more

- [Male, female and hermaphrodite cannabis: how sex works](https://genetixbay.com/knowledge/basics/sex-male-female-hermaphrodite.md)

## Sources

1. Divashuk MG, Alexandrov OS, Razumova OV, Kirov IV, Karlov GI. 2014. Molecular cytogenetic characterization of the dioecious Cannabis sativa with an XY chromosome sex determination system. PLoS ONE 9(1):e85118. https://doi.org/10.1371/journal.pone.0085118
2. Prentout D, Razumova O, Rhone B, et al. 2020. An efficient RNA-seq-based segregation analysis identifies the sex chromosomes of Cannabis sativa. Genome Research 30(2):164-172. https://doi.org/10.1101/gr.251207.119
3. Punja ZK, Holmes JE. 2020. Hermaphroditism in marijuana (Cannabis sativa L.) inflorescences: impact on floral morphology, seed formation, progeny sex ratios, and genetic variation. Frontiers in Plant Science 11:718. https://doi.org/10.3389/fpls.2020.00718