Don't know why I didn't count before . . . it's got 6 lobes, not 5 as an asclepiad would have. So likely a monocot.
:))) Hm... I'm in trouble: are they lobes?! I thought you mean lobes=petals... But, you are really very good at mathematics: it's got 6 "somethings", but I don't know the correct botanical name of this plantpart... :(
Not sure what the botanical term is either ;-) I was just thinking about comparing it to an asclepioid plant with 5 lobes in the flower (Hoya carnosa below; cropped from public domain pic http://commons.wikimedia.org/wiki/File:Hoya_carnosa.jpg )