I don't tend to think of clematis as 'shade plants' in general, and I've certainly proved this to myself numerous times by planting them in too deep of a shady situation hoping for them to find their way up/out and into the sun only to be disappointed, but I will 'third' the nomination, especially for part shade!
Highly recommend
makes a lovely part-shade interweaving groundcover!
Integrifolia and the many cultivars of
http://garden.org/plants/searc...
do well in what I would call 'more shade' for me
also the viticella types
http://garden.org/plants/searc...
do very well in part shade
