Nice burgundy colour. Big flowers. Starts blooming in later June and is continuous until frost. dies back and all new growth in spring. I have had it for over 6 years. bought as a bare root from Costco. Thanks

Could it be this one?
Clematis 'Warszawska Nike'

The petals seem longer and more pointy. Middle thing (not the technical term ) isn't as big either.

Ah, you're right! It just reminded me of the one I have (just got it this year ), but nope, that's not it. Pretty tho. Heh heh, may have to get me one of those when you find out what it is!

Could be 'Niobe' as it is one of the most widely sold clematis cultivars.

Clematis 'Niobe'

Take a look at "Niobe" and see what you think.
Clematis 'Niobe'

Ha! Cross posted. That was my thinking as well, that it would be something fairly well known.

I don't know Clematis very well but my vote is for Niobe too. It's one often sold at Costco and other big box stores.

I think it is Niobe, also.
But-

Google on: Home of Clematis

gets you to North America's leading Clematis growers.
They have a seasonal shop in Langley, B.C., Canada.