Beaming with regional pride, I found what I thought was New England Aster; I tried to identify it, and thought for one shocking moment that it was New York Aster! Then I looked into the field guide again and realized it could be any of a number of asters. If anyone can recognize it from these photos, I wouldn't care where it was from, I'd just be grateful.
The field marks are pretty hard to distinguish, I realize. I'm happy to call it an unidentified aster.