Wanderbloom

Wanderbloom is a common flowering plant found around the world. It is a hardy, assertive wildflower that grows as a weed in many biomes. Its flowers have an amazing contraceptive quality, providing absolute magical contraception for a full 24 hours after consumption. It is a year-round blooming plant and its flowers are also a common spice and preservative (the poor person's spice some have called it).
Wanderbloom was created by The Chimera near Asalay, and it has spread aggressively by both trade and its natural capacity for ecosystem invasiveness. It has revolutionized how sex and reproduction are approached around the world: having children has really become a choice. Dryads, whose flowering reproduction has a chance of producing young outside of their actual will (as pollen or pollinators have a chance of producing children essentially at random for any fertile flowering dryad), make an active effort to incorporate Wanderbloom into everyday life. Humans have largely followed suit.
That isn't to say that Wanderbloom is beloved everywhere. A number of states and power structures try and control the wildflower (though Wanderbloom's persistent weediness makes it difficult to control completely). Some have tried to ban it, others try to relegate its consumption to specific groups. Every place and every group is different.