Hi Guys,
I also brought Caroline Constable from a local nursery this year too, I paid $30 for a one gallon plant, it's tissue culture Itoh peony for sure. If your guys so interested in to buying more varieties of the Itoh peony, I think you should check out Quality Greenhouse in Dillsbury, PA, 17019. phone number is 7174328900, i found this information on the pot with Caroline constable, may be they will have more varieties available.
I hope this helps!