When you are inhaling pollen, your body has been penetrated by a little package of plant sperm. Pollen grains are multicellular organisms that contain male sex cells, and their job is to get this sperm to the egg to facilitate fertilization. For that, they hitch a ride on insects or trust their fate to wind, water, and any other moving means, including us. Yet most human-pollen encounters are only noticed when they result in an allergic reaction. Allergies have been on the rise, which is at least partly because pollen is too: Pollen counts have been going up in urban environments due to the tendency of city planners to plant male trees, which avoids problems with fruit falling on heads, cars, and sidewalks. Yet this also means that pollen is not absorbed by female trees and left roaming the streets to enter human noses instead. This self-made allergy problem demonstrates that we often seem to neglect what pollen is and does: As a miniscule sperm delivery mechanism, it is all about sex. Accordingly, pollen’s cultural history has predominantly been focused on attraction rather than allergic aversion, and because of that, pollen has shaped not only our understanding of plant fertility, but also human ideas about eroticism and sexuality, reproduction and desire.