Thanks Christine, I can see the petals better now.
Asclepias tuberosa is close, maybe a subspecies of it..
http://florapittsburghensis.wo...
Asclepias tuberosa Hello Yellow .. maybe an escapee as it's been 'tweaked'?
http://allanbecker-gardenguru....
http://www.abnativeplants.com/...
http://www.dyckarboretum.org/i...
A long list of Asclepias species!
http://luirig.altervista.org/g...
Drawings at the bottom, and a photo of the original A. tuberosa which still looks to have slightly broader petals and not as many.
http://luirig.altervista.org/c...
You will know better if the flowers match..
http://antsbeesbutterfliesnatu...
