Anchusa officinalis 'alba' - I cheated, I just went through the Gardens North on-line catalogue (but I figured it was in the borage family when I saw it, LOL!)
Nice plant. It will be interesting to know if it winters - I've tried Anchusa azurea a couple of times and not had it winter over, though it has come back from seed this last try.

Thanks ABgardeneer,
I didn't think to look at the GN on-line catalogue.
We usually get lots of snow here so a lot of perennials make it through the winter that might not otherwise, given winter temps.
Ian

Funny, it's the direct opposite here - very little snow that doesn't last - but "lots of perennials make it through the winter that might not otherwise, given winter temps".
Part of the secret is simply that many of these species have not been tried before, so no one really has an accurate idea of realistic zone ratings.
Lori