Sweet Autumn Clematis
It's pretty...and one of my favorites. I posted a picture of this a while ago, just when it was starting to come out in bloom. Upagainst the rocks in the back of this picture. I let it ramble all over everything...just like the looks of it that way. You can see Lily of the Valley; hostas, creeping phlox, ferns, astilbies, and a sunburst locus tree.
I have two of these...on opposite sides of the perennial garden. This and the next picture are of the other plant. It gets more sunshine so it's thicker and has more blooms.