The Pilea Microphylla Prostrata is also called the "waterfall fern." I saw this the other day at my local green house. They have a dripwall that flows into this little pond. Attached to the rockwall alongside the dripwall was this plant and it blew me away. It made a lush capet of tiny tiny leaves on a thin suculent type stem. It would add some really nice texture to a viv and an alternative background or carpet in the tank. The guy I was talking to there told me that he even keeps some of his in a terrarium. He also told me that cuttings grow great just wraped in moss and attached to the backwall. So I took a few cutings from the pot I bought and wraped them in some sphagnum and they were senging out roots in no time and starting new growth.