This is Boltonia Asteroides, also known as Doll’s Daisy. A butterfly attracter and a late-summer bloomer, I think it’s very well named because its blossoms look like shooting stars and just seem to be hanging in mid-air!
FROM WEEDS TO BEES
What's Happening in the Ruth Sisters' Yards All Over the Country
FROM WEEDS TO BEES 
Oh my goodness! You are right, Deb. The blooms do look like they are suspended in mid-air. Way cool!
They look like big, fluffy snowflakes falling through the air!
Robin