I thought it could be some kind of big Schlumbergera sp.,
I googled all the species native but didn't get a match. The leaves are much bigger than a regular Schlumbergera too.
http://floradobrasil.jbrj.gov....
I often found them in the wild as well as in gardens growing epiphytic on tree trunks..
These picture are taken in a friend's garden in Paraty.
