what is this vine?

I have this vine for over 2 decades. It was in front of the garage in my previous house. I moved it with me to my current house when I move. It has always been quite dormant until I replanted it in the more sunny spot where it currently is.


It is one of my favorite vine as it only bear a few precious flowers each season. It has the decades looking vine and yet it never dies even when it looks touch and go. Here is a series of photos I took in the last few days.

If you recognize what plant this is please leave me a comment. I tired Google image search without any useful result.

Update May 21 17:41 PST:
Seeing a flower has 7 petals I googled "flower with seven petals" and I was able to find images that match. But then paying more attention I realize some of mine has 6 and some has 7.

Judging from the attributes and appearance my vine is a clematis or Klematis. Here is a site called home of clematis.