Can you provide the link where you saw the picture of the same plant? It would help us help you.

Thanks for your reply jean001! The picture of the plant is on this site under perennials forum.The date is June 20,2007.Unfortunately ,it shows no flower or seedpod.
My plant has purple and green 1/3 to 1/2 inch thick tough stems that are ridged but not really square.The seed pod is papery,like a chinese lantern.It starts out green and is a five sided ridged globe that you can see through.The skin turns very papery and brown and opens up to reveal the seed with age.The seed can be 1/2 round and when cut open, spews out tiny tomato like seeds.It looks a little like a tomatillo but the flower is a 1 1/2" trumpet like a jimsonweed ,but smaller.It has to be very hardy as I live 1000' up a hill in Vermont! This ,to me, is a real stumper!
I hope someone can figure this out!

I searched the perennials forum & gallery but could not find any post dated June 20 havind a picture similar to what you describe.
Can you give a link, or beeter take a picture of your plant and post it here.

Hi,
I'm thinking Nicandra(Shoofly.)
Remy

Here is a link that might be useful: Rob's page about Nicandra