Grayfern

This gray moss is commonly found growing in large clumps On trees.
It is short, growing up to 2 inches (5 cm) tall. It forms in thick clumps and they are exceptionally hardy, and is overwhelmingly delicate; it struggles more than most during dry spells.
When mature, emerald kidney-shaped capsules grow at the end of long, lime green sporophytes, eventually opening up during the mid-summer to release thousands of spores; it can cause severe allergic reactions.