Jimsonweed (Datura stramonium) - green stems
2014-9-20 Cape May Bird Observatory, Cape May, NJ
All parts of the plant are toxic; flower, stems, leaves, seeds, roots
Here described as having both purple and green stems:
http://www.illinoiswildflowers.info/weeds/plants/jimsonweed.htm
Here also mostly plants with green stems:
http://luirig.altervista.org/schedenam/fnam.php?taxon=Datura+stramonium
Here described as having purple stems:
http://www.missouriplants.com/Bluealt/Datura_stramonium_page.html
"easily identified by its glabrous, purple stems, toothed leaves, and spiked fruits."