Name: Suzanne/Sue Sebastopol, CA (Zone 9a) Sunset Zone 15
Glad you all like it!
We have a local nursery here that specializes in rhododendrons and it has several large clematis planted throughout the property, this is Haku Ookan. I'll have to edit the banner and add the name. Clematis 'Haku Ookan'
I have seen them growing here and VitAlba is seen frequently. Specilised niche market and not commonly available. Another on my wish list, I suppose I will have to hunt around in nurseries.