I have freshly harvested A. purpurascens seeds and will email you.

I have Asclepias curassavica (orange/yellow) and (yellow). These can be grown as an annual in your zone. I also have Tweedia caerulea (blue milkweed). You can grow this as an annual also but you could pot this one and bring it in, in winter, and it will bloom better the second year.
I'm interested in your silene regia and Asclepias viridis.

Thank You for your response, domehome.
But I probably should have been more specific in my posting.
I really only want cold hardy to zone 5, US native species.