A hardy herbaceous perennial relative of the familiar half-hardy cup-and-saucer vine, C.scandens. Having white flowers it's not as spectacular as its tender relative but still a lovely thing. I grow it in a sunny spot on a well-drained but rich soil, with a thick strawy mulch in winter just to be on the safe side. It dies down completely in winter.
The only down side is perhaps its vigour - once it gets going it's a big plant capable of covering about 10-12ft in a single season so make sure you put it somewhere where it can roam free. It tends to start late and flower late too so provide warmth and shelter.