yes, I was thinking too it must be related to the other one I've posted after I've seen the photos of a Marcgravia on the Flickr link you gave in that thread..
There are only supposed to be two Marcgravia sps in the Rio state
http://floradobrasil.jbrj.gov....
But it could be an escapee like you say..
There are 19 species in the whole of Brasil:
http://floradobrasil.jbrj.gov....
