Anemone ID #3

Gene, I'm about to walk down the street to photograph A. sylvestris for comparison.  Back shortly...

And... (a few minutes later  ;))... here is Anemone sylvestris, about a foot tall, spreading:
       

Also, for comparison, here is our locally native Anemone canadensis, with leaves a bit broader yet (rampantly spreading also):
   

From this at least, I would not guess that your Anemone #3 is either... I'm sure no expert though!  Can anyone else help out?

Gene wrote:

Pure white flower, one per stem, about 10 inches off the ground.  Perennial.  I think this is A. sylvestris.  What do you think?

Very nice flower but no sylvestris. Sorry, no idea what it is!