Can anyone identify this flower. it is about 3 or 4 inches in diameter, and the photo was taken on August 16 in southcentral Pennsylvania (zone 6b or 7). The petals look like those of a dahlia to me, but the center seems different.

Thank you.

May be a variety of Chinese aster?

I agree, it looks like a variety of Chinese Aster and a really pretty one! Here's another for bloom comparison.

Thank you very much Paul and Lin. I think you have nailed the ID of my mystery flower.

On second thought, in looking at the description, the flower's diameter is described as 1 to 2 inches. This flower is much larger, 3 to 4 inches, similar to many dahlias. That doesn't sound like a China aster. Your thoughts?

csandt said: On second thought, in looking at the description, the flower's diameter is described as 1 to 2 inches. This flower is much larger, 3 to 4 inches, similar to many dahlias. That doesn't sound like a China aster. Your thoughts?

I submitted a database proposal to correct flower size because Chinese Aster flowers are 3-5 inches in size!