The clematis with six tepals could be Jackmanii. Jackmanii can have 4-6 tepals, yellow anthers. Tepal shape is correct, fairly long and pointed, curling back to make the blooms appear rounded. The pictures on the HMF link don't show the backside, but Jackmanii should have a pale purple-to-white reverse.

The clematis with 4 tepals could also be Jackmanii, although the anthers are the wrong color. The anthers look like Elsa Spath, but ES is lighter in color, less pointed, and should have more tepals.

Maybe someone else can offer a positive ID.

Gary

Here is a link that might be useful: Jackmanii on HMF

I think the one on the left could be Polish Spirit and the one on the right, Etoile Violette.
Mine aren't flowering at the moment so I can't be sure.

I agree with Maggie that the one on the left is most definitely "Polish Spirit"..I have two of him..and the right is Clematis "Etoile Violette"...Jeanne

Thanks, Maggie and Jeanne. I think you've nailed it. Gary, the Polish Spirit is listed as a "Jackmanii type" on COTWÂin fact, I think it was sold to me originally as a Jackmanii, but once it bloomed I realized that was a mistake. Best to all, GaryStPaul