Clematis??

I noticed this climbing flower the other day and I've been watching it develop ever since. I can't be sure but I believe it could be a native Clematis. The only time I've seen anything quite like it was in the Boronup Forest near Margaret River, many years ago. The interesting thing is, I can only find one climber, it doesn't appear to be growing anywhere else on Wombat Hollow. This was hard to photograph as it was growing above head height in a banksia bush. I would be very interested to hear from my blip buddies if they have any other thoughts.