I have the same thing as in the first pic growing on a piece of driftwood. It is fairly fermly attached and I haven't pulled any off because I like it. I never interdused it into my tank, I don't know where it came from. Seeing as it has been there for over a year with no harm to anything I say leave it be if you like it.
Hmmm.....it does look like a liver wort. I am moving some of it into my co2 tank to see what happens to it. Lauraleellbp - if you want it you can have it, there are just a few strands (a little more than what's in the cup). Although, I am not sure if it is worth the shipping costs. :hihi: