Just wondering why it isn't planted..
Most Ferns don't get planted. See if it looks like a Bolbitis species. Tie to wood or rock or plant little roots but do NOT bury the thick sideways root called the Rhizome.
It looks like Bolbitus to me. I've got one that has gotten pretty good sized in my 220. If you tie the root area onto a piece of DW or even a rock it will eventually adhere to it and continue to grow and spread. They are slow growers.
I don't know if they will. But if they are slick/glazed I doubt they would.
It's fine to leave it there. I've lost a couple baby pieces of bolbutis in my 220 before and when I finally accidently find it the little plant has always grown. I just stick it on a rock or DW and it eventually attaches and grows.