New cultivars are marketed as being just like the species, only with bigger flowers. Just like the original plant but a new dwarf size. The same as the common variety, but now an improved cold hardy version. It's all plusses, no takeaways.
Marketers never point out what gets lost in the breeding.
Case in point: sweetbay magnolia. Magnolia virginiana.
One of the key attributes of this small woodland native tree is its lemony scented flowers in June. Heavenly, or so I've read.
I wanted one, and I wanted that fragrance, especially as I planted it outside the bedroom window, to smell its lovely scent on a June morning when it flowered.
But I also wanted one that could take my winters, and was delighted to find this: ". . . and the cold hardiest variety is one developed by Jim Wilson called 'Moonglow'".
The description did not say " . . . but the fragrance was sacrificed in breeding this tree for cold tolerance." Nope, it didn't say that.
I don't know for a fact that the scent was lost as a result of selecting for cold hardiness. No literature mentions that.
But I do know I have never smelled any fragrance. And I do know that a gardener I met last winter told me his sweetbay magnolias are highly fragrant, just delightful on a June day, but he had never heard of a 'Jim Wilson Moonglow' cultivar, he only had species sweetbay magnolias.
Rose gardeners know that scent was one of the first things to be bred out of heirloom roses in the quest for disease resistance or long bloom. I suppose it's logical to think the same has happened with this magnolia.
I still love this tree. Its glossy leaves flutter outside the window, showing their silvery backs. The flowers are creamy white and pretty, and the tree flowers at a very young age.
With its leaves on in winter it can suffer from heavy snow. This was the worst, when snow the consistency of cement fell in late October one year, bending this upright tree all the way to the ground. It was literally lying down on the ground, Talk about winter tolerance! It sprang back up and survived.
The leaves are beautiful, the open habit does not block the window, the shape is perfect at the side of the house, and the flowers are so nice.
But it lost something on the way to becoming the perfect plant for my northern garden.
It kept all the great attributes of the species that the breeders wanted, plus it could handle a cold winter. But there was a loss in the process. It lost its scent.
(If any commenters want to write in that they grow this specific 'Moonglow' magnolia cultivar and it smells divine blooming in their gardens, please do so, but be aware that I am going to kill myself if that is true.)