Off the coasts of the Mediterranean islands of Sardinia, Corsica and the Balearics, there are a number of smaller islands, studding the sea like olives in a vast focaccia. On these sun-kissed islands there grows a plant with a feature entirely appropriate to the almost mythical setting. When this plant flowers, it releases a scent that seizes the nervous system like no other. It is the stench of a rotting, flyblown carcass.
The flower is aptly named the dead-horse arum. On the first day of flowering, it releases a potent cocktail of oligosulfides: sulfur-containing chemicals that, as reported this week in Nature, are identical to those produced as meat decays.
Marcus Stensmyr and colleagues from the department of crop science at the Swedish University of Agricultural Sciences in Alnarp worked with researchers at Italy's University of Cagliari to determine the function of the singular smelling flower. They wanted to confirm that the foul smell is used to trick blowflies into spreading its pollen. But also they wanted to investigate whether this was a case of genuine mimicry on the part of the plant. If it was, the odor that rises fetidly from the flower should have the same chemical composition as that emitted from a genuine carcass.