As I enjoy good friends and cheap coffee out on the deck, I am also savoring the sweet fragrance of the abundant white bloom of the black locust off in the distance. I know that black locust is a noxious weed that invades riparian environments; but they smell so good on such pleasantly warm spring days. Modern varieties are certainly better behaved and more colorful with their pink to purplish flowers, but their fragrance does not compare so well.
Earlier here on the deck, one of my friends and I discussed how modern Buicks are much safer than old classic Buicks are, but are not quite as elegant and stylish. It made me think of how decades ago, modern roses were developed for flower size, form, color and stem length, but in the process, were deprived of, among other qualities, their fragrance. Perhaps I would have been more attentive to my friend if the coffee were as potent as the fragrance of the black locust.
Modern varieties of many classic flowers are less fragrant than their ancestors were. This is because decades (and centuries) ago, fragrance generally had not been prioritized in breeding as much as were other physical characteristics, such as flower size, form, color and so on. The plants that were consequently used for breeding typically had the most visually appealing flowers, but lacked fragrance. Such disparity is actually quite natural among plants with variable flowers.
For example, most bearded iris that naturally have the biggest, fanciest and most brightly colored flowers are also the least fragrant. Their progeny that have become the modern varieties are just as flashy, and also, just as deficient of fragrance. Conversely, the relatively small and simple pale purple flowers of my favorite ‘Grandma Sheppard’ bearded iris are remarkably fragrant.
To the iris, this is all quite sensible. Their fragrance is not designed to impress us, but is merely intended to attract pollinators. If they are fragrant enough to entice the insects that bring them pollen, they do not need to waste any more effort on visual appeal. Without fragrance though, they can alternatively use color (including infrared and ultraviolet) to direct insect traffic where they need it to go in order to accomplish pollination. Almost all of the many varieties of iris prefer to specialize in one or the other; either fragrance or visual characteristics, but not both.
So many of the old classics seem to have lost some or most of their fragrance as they have ‘improved’ over the years because visual appeal has been prioritized more than fragrance. Besides flowering locusts, roses and iris, some types of honeysuckle, mock orange, sweet pea, violet, hyacinth, lily and even narcissus are less fragrant than their ancestors were. However, traditional as well as modern fragrant roses and iris seem to be gaining popularity. Fortunately, gardenia, lilac, wisteria, stock and the fragrant types of angel’s trumpet and jasmine are probably as potent as they have ever been because they have not been tampered with as much.