A small fern native to the Americas which has spread widely throughout the world by a variety of mechanisms.. Introduced into Europe, North and sub-Saharan Africa, China, Japan, New Zealand, Australia,
The water fern has naturalized over a wide geographic range in Ireland, although recorded in relatively isolated localities, it can be periodically troublesome in ponds and slow moving freshwater habitats. On the River Barrow and associated canals pockets of plants can be found throughout the system.
Identification
- Water fern forms floating rosettes up to a few centimeters diameter
- Composed of branched fronds with rows of imbricate leaves covered with dense papillae.
- It is initially green, becoming reddish late in the season. Globular spore-bearing structures sometimes develop below the fronds.
