If flowers emit a fragrance, whether sweet, heady, or even unpleasant, it obviously isn’t merely for the pleasure of us passersby! So why does a flower have a scent?
Flower Scent – First and Foremost a Question of Pollination
In nature, there is probably nothing that exists without a purpose. Starting with the fragrance of flowers, which, after the end of March’s capricious showers, can finally bask in the sun and exhale their scents… to the delight of walkers and gardeners alike.
Certainly, some plants release a nauseating odor instead in order to attract scavenger insects, such as the Arum, which has only a few days of blooming to lure flies…
But whether they smell sweet or sour, flowers all have, for the same good reason, a scent that is stronger or weaker: to attract insects and facilitate the movement of their pollen, in short, pollination itself.
Volatile Organic Compounds in Flower Scents
Chemically speaking, flowers actually emit volatile organic compounds (VOCs), whose very light molecules are easily vaporized into the air. These fragrances will be picked up by the olfactory receptors of insects, typically located on their antennae. They will thus associate a scent with the presence of pollen or nectar, which constitutes their food.
Even craftier, some plants can go so far as to reproduce the odor of insect female pheromones in order to attract males! Thus, as they move from one flower to the next, insects perform their role and pollinate plants by carrying pollen from bloom to bloom.
And the stronger the scent, which can vary with the weather or the time of day, the farther the signal travels.
But Also Other Messages
But the scents released by plants can also serve to send other messages, which explains why they devote about 10% of their daily energy needs to scent production. They can therefore also emit a precise odor in stressful situations, for example when water is scarce, during drought, or when temperatures are too high.
Similarly, these odors help these plants communicate with one another, something that is often overlooked.
Even more so, there is another one of their abilities that many people don’t realize: to bring rain, or at least contribute to it! Indeed, the VOCs released by flowers contribute to condensation, the gathering of water droplets, thereby aiding cloud formation and, ultimately, rainfall.
So this is how scent creates the conditions for its own survival…
