Emerald

This lime green or black moss is commonly found growing in tiny clumps In marshes.
It is massive, growing up to 10 inches (25 cm) tall. It forms in thin clumps and they spread and grow quickly, and is overwhelmingly resistant; it can easily endure being trodden on.
When mature, emerald triangular capsules grow at the end of short, lime green sporophytes, eventually opening up during the late autumn to release dozens of spores.