Emerald

This emerald moss is commonly found growing in medium-sized clumps On rotten logs.
It is enormous, growing up to 10 inches (25 cm) tall. It forms in small clumps, and is overwhelmingly light.
When mature, emerald circular capsules grow at the end of long, lime green sporophytes, eventually opening up during the late autumn to release thousands of spores; it can cause severe allergic reactions.