I'm wondering if it isn't a Peperomia...there are over 1000 species, almost all from the tropical Americas, but two that are commonly grown are P. obtusifolia and P. magnoliifolia, both having variegated cultivars, and often mistaken for each other. The leaves are highly variable in size and shape.
The closest photo I found is just captioned Peperomia sp.
http://toptropicals.com/pics/g...
A possibility?
