It’s that time of the year.

A large Chinese chestnut tree (Castanea mollissima) is in bloom near my house, and it’s once again filling the air with an . . . ammonia smell which is seriously unpleasant.

The culprits are nitrogen-containing volatile organic compounds (VOCs) which include (for you chemists out there) 1-pyrroline, 1-piperideine, 2-pyrrolidone, and phenethylamine.

What’s the deal? Presumably the tree evolved this smell to attract pollinators. A recent scientific study of Castanea mollissima in China identified the chestnut’s pollinators as flies.

Those researchers suggest that we should add Chinese chestnut to the list of plants that rely upon sapromyophily for a reproduction strategy.

That is, this tree emits a smell that deceives carrion flies into believing that they’re visiting rotting flesh.

Eww.

Naturally, I cannot help but imagine what it must have been like to be out in the forest when the mighty American chestnut (Castanea dentata), erstwhile queen of the mountainous forests in the eastern U.S., was in bloom.

And, hey, I’d happily cope with a couple of weeks of that yucky odor to have those trees back, safe and sound from the chestnut blight.