Aster laevis
A plant of old fields, forest openings, and so forth. Relatively uncommon; I know if from cultivated plants.
A pseudanthium on the Indiana University campus in Bloomington, 9/17/03.
A lower cauline leaf and developing axillary inflorescence on the IU campus, 9/17/03.
Developing pseudanthium, showing phyllaries, 9/17/03.