Why do flowers smell?

The luscious aroma of flowers attracts lovers, and the biological role of that smell is similar: to attract pollinators.. . .Plants and pollinators often display a long history of mutual evolution, Iltis adds. When Charles Darwin saw a flower with a foot-long tube during the 1800s, he predicted the existence of a moth with an equally long that could reach the female parts at the bottom of the tube. This moth was discovered more than a century later!

The minty, oily or sharp smells produced when you crush a leaf or stem play a defensive role, Iltis says. These smells come from chemicals that are often toxic to animals, and thus serve as a one-two punch: they smell (and taste) terrible, and then they make you sick if you ignore your senses and take a bite. . . .

Curiosities: Why do flowers smell, and why do plants smell, too?

But there is more to flower scents that that. Many are deliberate deceptions that evolved to trick pollinators into pollinating them while not receiving any pollen back as a reward.

Dendrobium sinense orchids on the Chinese island of Hainan, mimic the scent a honey bee makes when it is in distress. This scent is used to warn other bees to stay away. Hornets that eat the bees know the scent and land on the orchids producing the scent hoping to find food. The orchid gets pollinated, the hornet goes away hungry.

New orchid deception found: wearing the scent of hornet’s prey

Ophrys orchids give off the same scent that female bees give off when attracting a mate. Male bees come to the Ophrys orchid looking for a mate and pollinate the orchid while there. But it’s not just Ophrys, 18 of 20 orchids tested gave off at least trace amounts of alkenes.

Female bees are much better at pollinating plants, but male bees travel further. Plants who specifically target male bees will spread and receive pollen from a wider range of plants.

Evolution of sexual mimicry in the orchid subtribe orchidinae