Shadowfern

This black moss is commonly found blanketing tiny areas On trees.
It is colossal, growing up to 10 inches (25 cm) tall. It forms in large clumps and they overwhelm an area rapidly, and is overwhelmingly frail.
When mature, emerald kidney-shaped capsules grow at the end of short, lime green sporophytes, eventually opening up during the mid-summer to release dozens of spores; it does not cause any allergic reactions.