From what I can tell it's a banana plant on the rock. I've never heard of a banana plant attached to anything though. Does it have those things that go down at the bottom? A pic of the plant might be useful.
Planted 10 gallon tank; 2 x 10W CFL; Fluval U2; MGOCPM/PETCO black sand cap
The Fraternity of Dirt #152
A Silent Cycled Tank