Clematis? and if so which species?

Hi, all. My first post in this forum. I don't know where this came from and have never seen another around here. I do have a large climbing wild clematis that reseeds every so often. But this is completely prostrate (because nothing to grow on?). Also the leaves are much smaller than the wild one.
Anyone have a clue what it is? I first noticed it last year and haven't seen it bloom yet.