Hi Suzannie41, Yes they do. This species is Asclepias amplexicaulis and is really beautiful and easy to grow from seed. Just collect the seed as soon as the pods start to split and sow. They will germinate in a few weeks. The ones I collected last August(2009) and sowed did this and have remained nice plants outside in their winter containers enduring temps down to 11 in the past few weeks with no damage. Good luck.
Regards, Mark

Per the Monarch hostplant FAQ it is also known as
blunt-leaved, bluntleaf, or sand milkweed.

Larry, thanks for reminding me about the FAQ....I had no idea there were so many different kinds of milkweed.

There is a really good informational source at USDA website for the genus Asclepias. Click on the "P" beside each plant for detailed information including distribution range and additional links for further information. I find this very informative.

Susan

Here is a link that might be useful: Asclepias at USDA

Suzannie41 did you ever grow the clasping milkweed?