Looks like Clematis "Jackmanii" to me...Jeanne

Here is a link that might be useful: Jackmanii

There are so many dark purple ones

I'm a recent admirer of clematis, but it looks a little like Clematis Romantika in terms of the shape of the petals! See a picture here: http://www.homeofclematis.net/romantica.html Another that looks close is serenata: http://www.homeofclematis.net/srenata.html

Please post a follow-up if you figure it out! Or, if you don't and would consider sharing some seed, please e-mail at cjedzini@yahoo.com!

Good luck!