Hi Robin! So nice to see you over here.
I think the common variety, Symphytum officinale, from Europe can be either white or purple to pink. There's another Russian variety, S. ibericum, S. x uplandicum. They can set seeds, I don't know much more than that. My interest in comfrey was originally its medicinal value. It's been long established as a skin and bone healing plant. Its' also great as a manure crop or added to compost.
