That is polytrichum sp.
oldie but a goodie: How to Grow Sphagnum Moss
Last edited by Av8tor1; 12-06-2014 at 02:55 PM.
I never knew that.. I always thought it looked really nice and gives a real nature look. Didn't realize it actually did that. Will it stunt the growth of mature plants?
The smaller "carpet moss" variants can form a dense layer so thick that when you pull it up it takes the top inch of substrate with it.
Its a PITA, most growers use a top layer of live Sphagnum to prevent its growth.
Some of the nicer looking "Christmas tree" like species are suspected of being actively antagonistic toward other plant species.
(I don't know of any peer reviewed studies)
Stay with Sphagnum...