Is this 'Alaskan Seas'?
I got eight large rhizomes of this from my neighbor this August for dividing the clump it was in. I have tenatively identified it as "Alaskan Seas" and would like everyone's opinion. Since I just got it, I do not have height or bloom size. The date in the picture gives its bloom date. The clump was about 3 feet x 3 feet and produced about 40 rhizomes. It was in place when I moved to PA in 2005. My neighbor moved in in 2007, so she does not know anything about it.
I can add a couple more pictures if needed, but they are about the same as this one. Thanks.