This popular pond plant, originally native only to North and Central America, is also known as Fairy Fern
Water fern is a floating aquatic plant native to tropical America and is the only floating fern in Britain.
The leaves of water fern are no bigger than 2.5mm – forming small plants around 2.5cm long which cluster to form a dense mat and reduces oxygen levels in the water. Water fern floats on the surface of the water by means of numerous, small, closely-overlapping scale-like leaves, with their roots hanging in the water. The plants are so small, at no bigger than 2.5cm, that it can easily be transported on other plants as a contaminant.