Wildflowers: Darn if I know.

This volunteer wildflower is just outside my door, growing in sand. I didn't know what it was so let it go with hopes of it flowering. It came into bloom last night and now I'm not able to identify it.

The round, 1/4" dia. stalk is about three foot tall with single long, 4-5" serrated leave edges.

Thanks,
Richard

 

One of Campanula or Adenophora species.

 

I vote for Adenophora - simple venation and tiny hairs on the petal margin.