Plant breeders, farmers and gardening enthusiasts have for centuries been selectively breeding plants to develop plants with certain desired traits, be it larger roots or fruit, showy flowers or....
So if one chooses to plant that is the result of some breeding effort in an area where the original wild version is at home, could that have negative efects on the wildlife? Like cross-polinating and similar? And are there methods to avoid spreading of the cultivated type?
I distinctly remember some of the wild Bellis perennis in my parents' lawn suddenly showing a double layer of ray florets and pinker tinge after pink cultivated bellis were planted in a flowerbed nearby.
Would I risk a similar effect if I planted red-leaved variant of elder (S. niger 'Black Beauty', S. niger 'Black Lace') in my garden, in a region where Sambucus niger is growing wild? Short of cutting off all flowers before bloom, is there a way to avoid it? Or is the risk only theoretical?