Blue wood aster (Heart-leaf aster) Symphyotrichum cordifolium
In late September my deliberate neglect of the yard bears fruit. Tall rangy weeds in the shady corners and other places finally burst forth with bluish daisy-like flowers. This year one plant came up right in front of a frequently used gate--it took all of our collective patience not to pull the darned thing, but now it's made the transformation from weed to wildflower.
The side of the yard under the white pines is especially thick with blue wood asters.
Insects have eaten the foliage so thoroughly that it took me a while to find a heart-shaped leaf that was intact.
This species appeared on this blog as 365 urban species #269: Heart-leaf Aster.