‘Botanical Sexism’ Could Be Behind Your Seasonal Allergies
7th June 2026
Atlas Obscura, an impressively well-named site. (With thanks to VA Viper, a kindred soul.)
ONE DAY THIS PAST APRIL, the residents of Durham, North Carolina, saw the sky turn a peculiar but familiar shade of chartreuse. Enormous clouds of a fine, yellow-green powder engulfed the city. It looked, and felt, like the end of the world. “Your car was suddenly yellow, the sidewalk was yellow, the roof of your house was yellow,” says Kevin Lilley, assistant director of the city’s landscape services. Residents, quite fittingly, called it a “pollenpocalypse.”
Male trees are one of the most significant reasons why allergies have gotten so bad for citydwellers in recent decades. They’re indiscriminate, spewing their gametes in every direction. They can’t help it—it’s what evolution built them for. This is fine in the wild, where female trees trap pollen to fertilize their seeds. But urban forestry is dominated by male trees, so cities are coated in their pollen. Tom Ogren, horticulturalist and author of Allergy-Free Gardening: The Revolutionary Guide to Healthy Landscaping, was the first to link exacerbated allergies with urban planting policy, which he calls “botanical sexism.”
In trees, sex exists beyond the binary of female and male. Some, such as cedar, mulberry, and ash trees, are dioecious, meaning each plant is distinctly female or male. Others, such as oak, pine, and fig trees are monoecious, meaning they have male and female flowers on the same plant. It’s easy to identify female trees or parts—they’re the ones with seeds. And yet more, such as hazelnut and apple trees, produce “perfect” flowers that contain male and female parts within a single blossom. But while both monoecious and male dioecious trees produce pollen, Ogren claims the latter are primarily to blame for our sneezes and watery eyes.
Nothing is too obscure to escape Politial Incorrectness.