Although cannabis has an XX/XY sex determination system, which is presumably controlled by dosage effects of the sex chromosomes and with the Y chromosome serving as a robust marker for male plants, the genes that govern the development of male flowers are also located in other regions of the cannabis genome. For this reason, female (XX) plants can also produce pollen through suppression of ethylene receptors—as is routinely done in the production of feminized seeds. Researchers are currently working to identify the underlying genetic signaling pathways (Adal et al. 2021)in order to gain a better understanding of sexual organ development in cannabis.

Cannabis plants can exhibit hermaphroditism, in which male and female reproductive organs appear within the same floral structure. Monoecious varieties are also known and have already been commercialized, particularly for uses outside of flower production (Borin et al. 2021). These monoecious plants produce separate male and female flowers and predominantly carry XX sex chromosomes (Faux et al. 2014).

Research into sexual differentiation in cannabis is a dynamic field, with the number of publications increasing each year (Shi et al. 2025). Recently, the hemp research group at Cornell University identified both female and monoecious individuals with XY chromosomes as well as true male plants with XX chromosomes (Zahl 2024), raising further questions about the sexual development of cannabis.

Until genetic markers for hermaphroditism (Punja und Holmes, 2020) and for the likelihood of anther formation are identified, our best tool remains the detection of the Y chromosome. With the Y chromosome test from Hancochem, you can remove all true male plants from your crop. Nevertheless, you should continue to carefully monitor your plants for the occasional appearance of anthers.