Crap. Someone posted something really similar and somehow I missed it. The comment was an aster. Is this also an aster? I have a very different type of aster growing elsewhere in my yard, so I had discounted{{gwi:807}} them since they are very different-looking.

This post was edited by katisu on Sun, Sep 14, 14 at 18:33

Oh, the Asteraceae number in the tens of thousands! They range from artichokes to zinnias, and include also marigolds, lettuce, chrysanthemums, echinacea, daisies, and dandelions.

Your plant reminds me of Horseweed (Conyza canadensis), though Horseweed's flowers rarely open to that extent. But I expect it's something else.

After googling horseweed, I don't really think it looks too much like it. BUT...I do think I have some horseweed growing in my front yard, after seeing those pictures. Mine are still at the short and leafy stage.

I do think it is some type of Symphyotrichum, a small white aster ... of which there are many species to choose from.

Thanks!