

As far as I can ascertain this is a Clematis 'Winter Beauty'. A vigorous perennial evergreen variety. Why does it keep trying to grow on the outside of the wall? The outside faces South so catches the Sunlight throughout the day.
I've just ordered one as it will make a useful addition to the Virginia Creepers growing up the old tree stump. Add a bit of colour while the creeper is leafless during the Winter.