A one-of-a-kind flower endemic to Greece is believed to emit a scent similar to that of decomposing insects in order to attract one of its main pollinators, the coffin fly.

Flowers are usually associated with sweet, pleasant smells, but truth is that not all flowers smell nice. In fact, some smell like some of the grossest thing in the world, and that’s by design, because their pollinators are actually attracted to these disgusting scents. Take Aristolochia microstoma, a small flower endemic to Greece, which deceives its main pollinator, the coffin fly, by emitting a highly unusual mix of scents that includes a compound found in dead beetles. As their name suggests, coffin flies are attracted to carrion, to the scent lures them into the flower where they are trapped long enough to deposit any pollen they carry onto the female organs.

Photo © Stavros Apostolou

“Many Aristolochia species are known to attract flies with floral scents, for example mimicking the smell of carrion or feces of mammals, decaying plants, or fungi,” said Thomas Rupp, the main author of a study on the flower’s deceptive tactics. “But our curiosity was piqued by A. microstoma, a species known only from Greece: unlike other Aristolochia with their showy flowers, A. microstoma has inconspicuous brownish flowers that lie horizontally, partly buried or close to the ground among leaf litter or rocks. The flowers release an unpleasant, carrion-like smell, noticeable to people at a short distance.”

Until now, it was believed that Aristolochia microstoma was pollinated by small arthropods, like ants, but this recent study has shown that to be false. The foul-smelling cocktail emitted by the inconspicuous brown flowers contains several compounds that are very attractive to coffin flies.

“Very few plants are known to produce this compound, strongly suggesting that A. microstoma mimics an unusual fake ‘reward’ to attract specialist pollinators,” the authors of the study wrote. “Our results suggest that this is the first known case of a flower that tricks pollinators by smelling like dead and rotting insects rather than vertebrate carrion.”

Although many of the hundreds of flowers in the Aristolochia genus use deception to attract pollinators, they do it with pleasant scents and impressive-looking, colorful flowers. Aristolochia microstoma, on the other hand, are brownish flowers that lie horizontally, partly buried or close to the ground among leaf litter or rocks. Not the most inviting looking plants, but their off-putting scent is irresistible to coffin flies.