Pellia

Pellia, often sold under that name but more accurately Monosolenium Tenerum, is a liverwort rather than a true moss, forming flat ribbon-like fronds that branch out in an irregular, almost coral-like tangle instead of the fuzzy strands you'd expect from java moss. It's slow growing and stays low, making it a solid choice for foreground texture or attaching to driftwood and rock where you want something denser and darker green than typical mosses. Tie it down and it'll root itself in over several weeks, holding up well under moderate light without demanding much in the way of ferts or CO2. Shrimp keepers love the tangled structure since it traps biofilm and gives babies plenty of places to vanish into.