Amblystegium serpens

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Amblystegium serpens, commonly known as creeping feathermoss or nano moss, is a small moss that is common in Britain. It forms creeping mats with leaves that are oval to spear-shaped and end in a fine point. The mats grow on damp, shaded surfaces such as decaying tree stumps and hedgebanks. The moss can even grow underwater for periods and is sometimes used in home freshwater aquariums as a decorative plant.