Does devil's trumpet grow wild in Long Island and New York?
Looks like Datura stramonium probably does http://plants.usda.gov/java/county?state_name=New%20York&statefips=36&symbol=DAST
D. inoxia and D. wrightii also occur elsewhere in NY so it's possible they could be there too. The county distribution map doesn't show them there, but since they're elsewhere in the state it's possible there could be some and they just haven't been catalogued & included in the map. http://plants.usda.gov/java/stateSearch?searchTxt=datura&searchType=Sciname&stateSelect=US36&searchOrder=1&imageField.x=65&imageField.y=13 But if you're seeing them growing in the wild D. stramonium is probably the most likely given the distribution (if you post some pictures someone could confirm)
The plants I saw are the double purple variety growing by train tracks.
I've grown those in the garden from seeds shared by other DGers. And there is a double purple in the seed trade.
Area behind us was bulldozed for construction. One year there was a good acre or two of absolutely covered with white Datura plants, where had been pasture with the occasional one. It is a genus that can take advantage of certain situations, with "wild abandon.".
Datura seeds can live for years. Oh, wow, so can threads. Never mind. I got rid of my datura and after about 5 years quit seeing seedlings pop up. I cannot imagine having an acre, and it is poisonous to cattle I believe too.