Asplenium aff. fragrans

This fern is found in Peru and Ecuador, and likely elsewhere in south America.  It thrives in low to medium light, and abundant moisture, although it will do well growing on a vertical branch so long as humidity is high.  The one below is Ecuadorian and gets quite large, about 10″ tall (and possibly even taller), but there is a small Peruvian form that only gets about 4 inches.  They can both form beautiful colonies with enough time, the  rhizome base being quite dense and strong.

And here, growing on a vertical branch.  It seems to grow best this way, so long as its rhizome is protected with moss.