clematis id please
 

Sorry, no pic-the clematis in question is up a rowan tree, and i can't get close enough for a pic. I grew it from seeds marked C integrifolia, but it obviously isn't that.

It's climbed to about 20ft, is in flower now in Yorkshire (which is equivalent to mid Feb further south), ie very early - earlier than C armandii. 4 petalled cream flowers, sort of bell-shaped, ie not opening out flat, petals slightly rounded (not as elongated as alpina petals). The plant has leaves on at the moment, which I suppose counts as evergreen (though it doesn't have a lot of leaves).

My best id is a non-freckled cirrhosa, but are there any other possibilities?