What's the name of this contraceptive plant ?

Maybe ten years ago I stumbled upon a random fact about a people that ate an ungodly amount of some contraceptive plant as part of their diet and thus (lets be cautious with exceptional claims) was *supposedly *unaware of any link between having children and the birds and the bees. I'd like to include a reference to this story in a current content I'm making but i can't find anything about any of this on google. I also asked ChatGPT but it always asks for more context that I obviously can't provide.

Any help finding the name of this plant ?