Water fern

Water fern is a common name for several plants and may refer to:


Azolla (mosquito fern, duckweed fern, fairy moss, water fern) is a genus of seven species of aquatic ferns in the family Salviniaceae. They are extremely reduced in form and specialized, looking nothing like other typical ferns but more resembling duckweed or some mosses. Azolla filiculoides is one of just two fern species for which a reference genome has been published.

Azolla filiculoides

Azolla filiculoides (water fern) is a species of Azolla, native to warm temperate and tropical regions of the Americas as well as most of the old world including Asia and Australia.

It is a floating aquatic fern, with very fast growth, capable of spreading over lake surfaces to give complete coverage of the water in only a few months. Each individual plant is 1–2 cm across, green tinged pink, orange or red at the edges, branching freely, and breaking into smaller sections as it grows. It is not tolerant of cold temperatures and, in temperate regions it largely dies back in winter, surviving by means of submerged buds. Like other species of Azolla, it can fix nitrogen from the air.

Fossil records from as recent as the last interglacials are known from several locations in Europe (Hyde et al. 1978).

Azolla filiculoides is one of just two fern species for which a reference genome has been published.


A biofertilizer (also bio-fertilizer) is a substance which contains living microorganisms which, when applied to seeds, plant surfaces, or soil, colonize the rhizosphere or the interior of the plant and promotes growth by increasing the supply or availability of primary nutrients to the host plant. Biofertilizers add nutrients through the natural processes of nitrogen fixation, solubilizing phosphorus, and stimulating plant growth through the synthesis of growth-promoting substances. Biofertilizers can be expected to reduce the use of synthetic fertilizers and pesticides. The microorganisms in biofertilizers restore the soil's natural nutrient cycle and build soil organic matter. Through the use of biofertilizers, healthy plants can be grown, while enhancing the sustainability and the health of the soil. Since they play several roles, a preferred scientific term for such beneficial bacteria is "plant-growth promoting rhizobacteria" (PGPR). Therefore, they are extremely advantageous in enriching soil fertility and fulfilling plant nutrient requirements by supplying the organic nutrients through microorganism and their byproducts. Hence, biofertilizers do not contain any chemicals which are harmful to the living soil.

Biofertilizers provide "eco-friendly" organic agro-input. Biofertilizers such as Rhizobium, Azotobacter, Azospirilium and blue green algae (BGA) have been in use a long time. Rhizobium inoculant is used for leguminous crops. Azotobacter can be used with crops like wheat, maize, mustard, cotton, potato and other vegetable crops. Azospirillum inoculations are recommended mainly for sorghum, millets, maize, sugarcane and wheat. Blue green algae belonging to a general cyanobacteria genus, Nostoc or Anabaena or Tolypothrix or Aulosira, fix atmospheric nitrogen and are used as inoculations for paddy crop grown both under upland and low-land conditions. Anabaena in association with water fern Azolla contributes nitrogen up to 60 kg/ha/season and also enriches soils with organic matter.Other types of bacteria, so-called phosphate-solubilizing bacteria, such as Pantoea agglomerans strain P5 or Pseudomonas putida strain P13, are able to solubilize the insoluble phosphate from organic and inorganic phosphate sources. In fact, due to immobilization of phosphate by mineral ions such as Fe, Al and Ca or organic acids, the rate of available phosphate (Pi) in soil is well below plant needs. In addition, chemical Pi fertilizers are also immobilized in the soil, immediately, so that less than 20 percent of added fertilizer is absorbed by plants. Therefore, reduction in Pi resources, on one hand, and environmental pollutions resulting from both production and applications of chemical Pi fertilizer, on the other hand, have already demanded the use of phosphate-solubilizing bacteria or phosphate biofertilizers.

Blechnum cartilagineum

Blechnum cartilagineum is known as the gristle fern or soft water fern. It is a resilient and abundant fern growing in eastern Australia. Seen in rainforest and eucalyptus forest. New growth is often pink or reddish in colour.

It is very tolerant of dry conditions once established in a shady area.

Blechnum fluviatile

Blechnum fluviatile is a fern known in the Māori language as kiwikiwi. A herbaceous plant, B. fluviatile is a "hard fern" of the genus Blechnum in the family Blechnaceae. It was identified by Patrick Brownsey in 1979. Other common names are star fern, creek fern, kawakawa and kiwakiwa.

Blechnum indicum

Blechnum indicum or the swamp water fern is often seen growing on sandy soils in swampy areas. The specific epithet indicum is from Latin, revealing this plant was first collected in the East Indies (Java). Indigenous Australians used the starchy rhizome as food.

This plant was collected with another swamp fern Cyclosorus interruptus by Joseph Banks and Daniel Solander at Botany Bay in 1770.

Blechnum nudum

Blechnum nudum (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.

Blechnum patersonii

The strap water-fern (Blechnum patersonii) is a fern in the genus Blechnum.

It is native to Australia.

Blechnum penna-marina

Blechnum penna-marina, Antarctic hard-fern, alpine water fern, pinque (Chilean Spanish), is a species of fern in the family Blechnaceae, with a natural range from the Araucanía Region to the south and from the coast to the tree line of the Magellanic forests in Chile and adjacent areas of Argentina. It is also found in New Zealand, Australia and some Pacific islands. It is evergreen and grows to 20 cm (8 in).

In cultivation this hardy species has gained the Royal Horticultural Society's Award of Garden Merit.

Blechnum wattsii

Blechnum wattsii or the hard water fern is a common terrestrial fern growing in rainforest and open forest. Often seen near creeks in much of south eastern Australia, including Victoria, Tasmania (and King Island), South Australia, New South Wales and Queensland. The Blechnum wattsii was named for Reverend William Walter Watts (1856-1920). Reverend Watts was considered an authority on mosses and ferns and has more than 30 species named for him. Common names by which B. wattsii may be called are hard water fern - from its stiff leathery fronds, leech fern - as forest workers often encounter leaches while working in clusters of these ferns, hard hill fern - from the fern's habit and habitat, and red cabbage fern - from the bronze-pink colour of the young fronds resembling cooked red cabbage.

Bolbitis heudelotii

Bolbitis heudelotii, also known as the African water fern, creeping fern, and Congo fern, is native to subtropical and tropical Africa, from Ethiopia west to Senegal; and down to northern South Africa.

Bánh bèo

A bánh bèo is a Vietnamese dish that comes from Hue, a city in Central Vietnam. The English translation for this dish is water fern cakes. Bánh bèo is made from a combination of rice flour and tapioca flour. It is popular street food in Vietnam. The ingredients include rice cake, dried shrimps, crispy pork skin, scallion oil, and dipping sauce. It is usually eaten as a snack but is now considered a dish in restaurants and can be eaten as lunch and dinner.


A fern is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. They differ from mosses by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the sporophyte is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns, sometimes referred to as true ferns. They produce coiled fiddleheads that uncoil and expand into fronds. The group includes about 10,560 known extant species.Ferns are defined here in the broad sense, being all of the Polypodiopsida, comprising both the leptosporangiate (Polypodiidae) and eusporangiate ferns, the latter itself comprising ferns other than those denominated true ferns, including horsetails or scouring rushes, whisk ferns, marattioid ferns, and ophioglossoid ferns.

Ferns first appear in the fossil record about 360 million years ago in the late Devonian period, but many of the current families and species did not appear until roughly 145 million years ago in the early Cretaceous, after flowering plants came to dominate many environments. The fern Osmunda claytoniana is a paramount example of evolutionary stasis; paleontological evidence indicates it has remained unchanged, even at the level of fossilized nuclei and chromosomes, for at least 180 million years.Ferns are not of major economic importance, but some are used for food, medicine, as biofertilizer, as ornamental plants and for remediating contaminated soil. They have been the subject of research for their ability to remove some chemical pollutants from the atmosphere. Some fern species, such as bracken (Pteridium aquilinum) and water fern (Azolla filiculoides) are significant weeds world wide. Some fern genera, such as Azolla can fix nitrogen and make a significant input to the nitrogen nutrition of rice paddies. They also play certain roles in mythology and art.

Grantham Canal SSSI

Grantham Canal SSSI is a 9.5-hectare (23-acre) biological Site of Special Scientific Interest which runs along a stretch of the Grantham Canal and its banks between Redmile and Harby in Leicestershire.This site has diverse aquatic and terrestrial habitats, which supports a varied insect community. The canal has floating plants such as fat duckweed and water fern, and there are breeding birds such as sedge warblers, moorhens and reed warblers.There is access to the canal towpath.

Rainforest in Victoria (Australia)

Victoria, Australia contains approximately 32,000 hectares of temperate rainforest in various regions, which represents 0.14% of the State's total area. The areas with rainforest include: East Gippsland, Strzelecki Ranges, Wilsons Promontory, Central Highlands, and Otway Ranges. The rainforests vary between cool temperate, warm temperate, and mixed cool temperate.


Regnellidium is a monotypic genus of ferns of family Marsileaceae.

The single living species, Regnellidium diphyllum, the two-leaf water fern, is native to southeastern Brazil and adjacent regions of Argentina. It resembles its relatives from the genus Marsilea, but has 2-lobed leaves (rather than 4). This fern is sometimes grown in aquaria.

A fossil assigned to the species Regnellidium upatoiensis has been found in Cretaceous deposits of the eastern United States.

Salvinia molesta

Salvinia molesta, commonly known as giant salvinia, or as kariba weed after it infested a large portion of Lake Kariba, is an aquatic fern, native to south-eastern Brazil. It is a free floating plant that does not attach to the soil, but instead remains buoyant on the surface of a body of water. The fronds are 0.5–4 cm long and broad, with a bristly surface caused by the hair-like strands that join at the end to form eggbeater shapes. They are used to provide a waterproof covering. These fronds are produced in pairs also with a third modified root-like frond that hangs in the water.

Samea multiplicalis

Samea multiplicalis, the salvinia stem-borer moth, is an aquatic moth commonly found in freshwater habitats from the southern United States to Argentina, as well as in Australia where it was introduced in 1981. Salvinia stem-borer moths lay their eggs on water plants like Azolla caroliniana (water velvet), Pistia stratiotes (water lettuce), and Salvinia rotundifolia (water fern). Larval feeding on host plants causes plant death, which makes S. multiplicalis a good candidate for biological control of weedy water plants like Salvinia molesta, an invasive water fern in Australia. However, high rates of parasitism in the moth compromise its ability to effectively control water weeds. S. multiplicalis larvae are a pale yellow to green color, and adults develop tan coloration with darker patterning. The lifespan, from egg to the end of adulthood is typically three to four weeks. The species was first described by Achille Guenée in 1854.

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