I've never known them to spread, is it a possibility that there was some root stock included in the daisy pot when you planted?

Violet, this bed has been planted for several years. The only new addition was the native aster planted a couple of years ago. I have taken lots of pictures of this bed and the aster was never there before. I have had lots of strange things in my gardening year.

For instance, I planted my usual white-seeded pole bean Kwintus this year on the hoop house frame. When I did my first picking I saw lots of long, slender, 'round' podded beans along with the flat Roma-like Kwintus. I am letting seeds mature now and the new round one is a light brown color........I had only planted Kwintus last year and besides this was new seed this year. I am assuming Park's source had a cross last season.

Interesting, interesting!

Well. I found another seedling; this time growing out of a 3x6 inch crack in a concrete ledge in the middle of this bed where gas tank stands used to rest. So it is definitely spreading by seeds.

Surprises are nice. Do you have baby columbines?