I think I found it. This was on an excellent website for plant ID (short for identification) that makes it simple to search by state, sun or shade, etc.
http://www.wildflower.org/plants/
But, not sure yet of edible status, will add more as I find it......but this is what it looked like and fit the most closely
Acalypha rhomboidea Raf.
Common threeseed mercury, Virginia threeseed mercury
Euphorbiaceae (Spurge Family)
And the news..IF THIS IS IT.......(I'm not so sure now,)
.good is the birds would love the seeds.
Not so good, it's very invasive and as its in the euphorbia (spurge) family it will have a milky sap that can irritate. I do not think the chickens would find it palatable, but....probably not something you want them to eat very much of.
Maybe someone else has experience with it, but it doesn't grow out west (yet

) so I'm just going by the web reports.
So a quick test would be to snap a stem and see if there's a milky sticky liquid.
If that isn't it I'd grab a piece of it and (maybe do that anyway come to think of it) and have it in hand (at the website above) while you compare it to the list of possible matches. Hint. Put multiple choices in your searches. Ie check off both "sun" and "shade"; "under 1' and "1 - 1/2', ; "dry" and "moist" soil. It broadens the search to cover different conditions.
Sorry couldn't be more confident. Maybe a better picture would help....