Water fern is a common name for several plants and may refer to:
Blechnum, known as hard fern, is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. Two very different circumscriptions of the genus are used by different authors. In the PPG I system, based on Gasper et al. (2016), Blechnum is one of 18 genera in the subfamily Blechnoideae, and has about 30 species. Other sources use a very broadly defined Blechnum s.l., including accepting only two other genera in the subfamily. The genus then has about 250 species. In the PPG I circumscription, the genus is mostly neotropical, with a few southern African species.
Austroblechnum divergens, synonyms including Blechnum divergens, Blechnum rimbachii and Blechnum floresii, is a species of fern in the family Blechnaceae.
Struthiopteris spicant, syn. Blechnum spicant, is a species of fern in the family Blechnaceae, known by the common names hard-fern or deer fern. It is native to Europe, western Asia, northern Africa, and western North America. Like some other species in the family Blechnaceae, it has two types of leaves. The sterile leaves have flat, wavy-margined leaflets 5 to 8 millimeters wide, while the fertile leaves have much narrower leaflets, each with two thick rows of sori on the underside.
Neoblechnum is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, with a single species Neoblechnum brasiliense, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily; the species is then known as Blechnum brasiliense. It is called Brazilian dwarf tree fern, red Brazilian tree fern, and red dwarf tree fern.
Cranfillia fluviatilis, synonym Blechnum fluviatile, is a fern known in the Māori language as kiwikiwi. A herbaceous plant, C. fluviatilis is a "hard fern" of the genus Cranfillia in the family Blechnaceae. It was identified by Patrick Brownsey in 1979. Other common names are star fern, creek fern, kawakawa and kiwakiwa.
Parablechnum cordatum, the Chilean hard fern or costilla de vaca, is a fern of the family Blechnaceae, native to Chile. It is also found in neighboring areas of Argentina and the Juan Fernández Islands.
Lomaria discolor, synonym Blechnum discolor, commonly called crown fern, is a species of fern in the family Blechnaceae. This species is endemic to New Zealand. As noted by C. Michael Hogan, this species is found in a number of forest communities in diverse locations within New Zealand, and is sometimes a dominant understory component.
Austroblechnum lanceolatum, synonym Blechnum chambersii, is a species of fern within the family Blechnaceae, found in Australia, New Zealand, Samoa and Fiji.
Lomaria nuda, commonly known as the fishbone waterfern, is a fern that grows up to a metre tall, and is abundant in rainforest and eucalyptus forests in eastern Australia. The species is placed in the genus Lomaria in the Pteridophyte Phylogeny Group classification of 2016, but is often retained in genus Blechnum as Blechnum nudum.
Austroblechnum patersonii, synonym Blechnum patersonii, is a fern in the family Blechnaceae. It is known as the strap water-fern.
Lomariocycas tabularis, synonym Blechnum tabulare, known as the mountain blechnum is a large, attractive fern that is indigenous to sub-saharan Africa.
Oceaniopteris gibba, the miniature tree fern, is a tropical species of fern in the family Blechnaceae, native to New Caledonia and introduced in Fiji. It has received the Royal Horticultural Society's Award of Garden Merit.
Parablechnum minus, synonym Blechnum minus, is a small fern growing in moist situations in a variety of habitats in eastern Australia. It is often seen by streams.
Parablechnum novae-zelandiae, synonym Blechnum novae-zelandiae, commonly known as palm-leaf fern or kiokio, is a species of fern found in New Zealand. It can often be found growing in clay soil on embankments and roadsides.
Cranfillia fullagari, synonym Blechnum fullagarii, is a fern in the family Blechnaceae. The specific epithet honours James Fullagar, who collected plants on Lord Howe Island for the Royal Botanic Gardens, Melbourne.
Parablechnum gregsonii, synonym Blechnum gregsonii, is a type of fern, mostly seen in the Illawarra and Blue Mountains areas of eastern Australia, often near waterfalls and moist gullies.
Oceaniopteris is a genus of ferns in the family Blechnaceae, subfamily Blechnoideae, according to the Pteridophyte Phylogeny Group classification of 2016. The genus is accepted in a 2016 classification of the family Blechnaceae, but other sources sink it into a very broadly defined Blechnum, equivalent to the whole of the PPG I subfamily.
Blechnum occidentale is a fern in the family Blechnaceae. Its native range is from Mexico through Central America and the Caribbean to tropical South America.
