Brownfern

This brown moss is commonly found growing in medium-sized clumps In heathlands, On trees, and In moorlands.
It is short, growing up to 1 inch (3 cm) tall. It forms in thick clumps and they are exceptionally hardy, and is overwhelmingly light.
When mature, emerald oblong capsules grow at the end of long, lime green sporophytes, eventually opening up during the early summer to release millions of spores.