Looking for information on clumping vine

This vine is growing in my part-shade garden between one of my hostas and a patch of lamb's ear. It's absolutely thriving, but I wonder what it is? It seems to have a clumping habit, as all the roots stay politely within one small area, and it just forms an extremely dense, jungle-like mound. Occasionally a tendril or two strays near the hosta, but I just pull it back. It doesn't seem to "grip" anything, it just scrambles.

Its clumping habit makes it a nice place for snails and slugs to hide during the day, but little do they know how that works against them! Because the roots stay within an 8-inch radius, I simply pick the vine up in one giant clump and "harvest them" where they lie. The vine system itself is so incredibly dense, I've never found anything hiding inside. What's strange is that I've seen no sign of the snails and slugs eating the vine itself.

As you'll see in pics I'll post in replies, the leaves are serrated on one edge only, and not all leaves are the same. I don't see any buds forming on this vine at all. I had originally planned to yank this and transplant it, but I"m leaving it where it is for now since it doesn't seem to act invasive. My toad house looks very cute sitting next to this curly, attractive vine.

Here it is from the top:

Here is a close-up of the leaves. Notice the serration on one side only:

Looks like Clematis terniflora to me... http://davesgarden.com/pf/go/683/index.html ...which would have flowers if grown in a sunny location beginning around late August or September in your area. :-)

Thanks, Nifty. I think you may be right. I didn't see any serrations on the leaves of the Plant Files photos, but not all mine have them anyway. I'd love to think this was the beautiful clematis, because I've fallen in love with the scent of those flowers every year! Never knew what it was, though.

I wonder if it's too late to transplant this year?

If you poke an obelisk in the soil and start to train it that puppy will climb as tall as the support is. And full sun but mulch the roots. Here's a pic of mine I took this today.

Here's a closeup of one flower

Momo, that's beautiful! That makes me really hope it's not too late to transplant, because I would love to get blooms like that.

I love the obelisks. I have one for my passion flower vine, and it couldn't be happier. I have a blue passion flower seedling coming up (finally!), and I plan to get an obelisk for it as well.