One of my hobbies is photographing flowers and adding their common & botanical names, but I am virtually never able to identify them, so I almost always need help.
I made my traditional mistake and did not take a wide view to help with identification. Perhaps the crude picture will help some.
The blossom is about 1 1/2" across and has a 2-3" quite slender stem. They are not clustered. There were many in the field but they were individual plants mostly separated by 6-10"
At first I thought this was an Aster, but according to Wikipedia [The definition of Aster] has been narrowed, and it now encompasses around 180 species, all but one of which are **restricted to Eurasia**. So, even if it is what was earlier the genus Aster I don't know what the genus of this one is.
I have doubts about it being being an an aster at all because I've been unable to find a picture on the web of the flower many still call an Aster that has an array around the floral disk like this one.