Calotropis procera - Now that's a tough one. I see that it sometimes goes by the name of "Apple Of Sodom", but so does the unrelated plant
Solanum linnaeanum. I did notice though that it is native to Africa and hence not a plant naturally associated with the Monarch Butterfly. I also noticed that in places it is classified as a rare plant. I could not find it among my seed sources. Please keep us up to date on your hunt!
