I have yet to have a chance to observe this phenomena as I have only smelled the flowers during midday and there is no detectable scent.  In the wild it has been observed that in the night hours the plant smell strongly of chocolate.    Over the last several days all of the facts that I have quoted in my posts were found at the following link: http://botanyvn.com/cnt.asp?param=news&newsid=1443&lg=en  I encourage all of my readers to give the article a look-see.  Here is a photo of the entire plant at less than 3 months from cutting: