Roses are red. Violets are blue.
Well, not just blue. At this time of year, all kinds of colours appear from the Viola family in the shape of pansies and bedding violas and garden centres will also be stocking up on the perennial species ready for spring colour. We also have wild violets, including the dog violet and, most famously, the sweet violet, Viola odorata.
The sweet violet, however, is an elusive mistress with her fragrance. We have all smelled the pungent, somewhat dry fragrance of parma violets, whether the sweets or old-fashioned perfume, yet the flowers have a quirky trait you may not know.
If you breathe in the scent of sweet violets you will notice that if you immediately try to take another sniff you will be unable to smell it again. Don’t worry, it’s only a temporary sensation, called anosmia, but an odd one, nonetheless. After a few minutes you will be able to smell the flower again, but take another whiff and the anosmia kicks in once more.
No, you’re not going mad and it’s not because the plant only produces a certain amount of scent, but it lies deeper in the chemistry of the fragrance. A ketone, called ionone, stimulates and then binds with our scent receptors for a short period of time. It’s not until a few moments later, after this compound has dispersed, that we are again able to appreciate the violet’s scent.
This gives our brains the impression that every time we smell a sweet violet it’s the first time we’re smelling it, whereas as most fragrances stay with us and we become accustomed to them, for instance, that of roses or lavender.
So next time you’re walking through the woods, it’s worth getting down on your knees just to smell the sweet scent of violets, because it’ll feel like the very first time all over again (to your brain, at least).