On June 24 I posted a photograph which I tentatively identified as Wild Chervil. I used the book Wildflowers of Vermont, 2nd edition by Kate Carter (2001) and National Audubon Society Field Guide to North American Trees: Eastern Region (Eastern). I finally settled on my wild chervil identification because of the Carter book which seems to have had an error (see the last photo below).
On July 14 TrinkaVermont left a comment that this was not wild chervil but yarrow. After spending the afternoon reading about these two plants and using a link she supplied, I must agree. I have documented some of the material used for my decision and posted it below.
Yarrow is a wildflower frequently planted in flower gardens. Wild Chervil has two plants by the same common name but two different Latin names. The one we are concerned with in Vermont is Anthriscus sylvestris and it is a dangerous noxious invasive pest. There are statewide programs to eradicate the state of it. We must learn how to identify it. Once identified it must be eradicated properly or we can inadvertently help it spread.
I found two excellent sources of identification and eradication information:
UVM: Invasive Plant Information for Vermont: Identifying Wild Chervil
The Herald of Randolph, VT: Wild Chervil Information Center
Finally, I cannot find TrinkaVermont to thank her for her identification. I have used Google Blog Search, Google search and a Flickr search. If any of you know her, please pass on my thanks.