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A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of
vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
s (plants with
xylem Xylem is one of the two types of transport tissue in vascular plants, the other being phloem. The basic function of xylem is to transport water from roots to stems and leaves, but it also transports nutrients. The word ''xylem'' is derived from ...
and
phloem Phloem (, ) is the living biological tissue, tissue in vascular plants that transports the soluble organic compounds made during photosynthesis and known as ''photosynthates'', in particular the sugar sucrose, to the rest of the plant. This tran ...
) that reproduce via
spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
s and have neither
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s nor
flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s. The polypodiophytes include all living
pteridophyte A pteridophyte is a vascular plant (with xylem and phloem) that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. Ferns, ...
s except the
lycopods Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...
, and differ from
moss Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) '' sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hor ...
es and other
bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in ...
s by being vascular, i.e., having specialized tissues that conduct water and nutrients and in having life cycles in which the branched
sporophyte A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...
is the dominant phase. Ferns have complex
leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
called
megaphyll In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of ...
s, that are more complex than the
microphyll In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of ...
s of
clubmosses Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...
. Most ferns are
leptosporangiate fern The Polypodiidae, commonly called leptosporangiate ferns, formerly Leptosporangiatae, are one of four subclasses of ferns, and the largest of these, being the largest group of living ferns, including some 11,000 species worldwide. The group has ...
s. They produce coiled
fiddleheads Fiddleheads or fiddlehead greens are the furled fronds of a young fern, harvested for use as a vegetable. Left on the plant, each fiddlehead would unroll into a new frond (circinate vernation). As fiddleheads are harvested early in the sea ...
that uncoil and expand into
frond A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...
s. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the
Polypodiopsida A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except th ...
, comprising both the leptosporangiate (
Polypodiidae Polypodiidae may refer to: * Polypodiidae (cnidarians), a zoological family that only includes ''Polypodium hydriforme'', a cnidarian parasite of fish eggs *Polypodiidae (plant), a botanical subclass of Equisetopsida sensu lato that includes the le ...
) and
eusporangiate fern Eusporangiate ferns are vascular spore plants, whose sporangia arise from several epidermal cells and not from a single cell as in leptosporangiate ferns. Typically these ferns have reduced root systems and sporangia that produce large amounts of ...
s, the latter group including
horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Eq ...
s,
whisk ferns ''Psilotum'' is a genus of fern-like vascular plants. It is one of two Genus, genera in the Family (biology), family Psilotaceae commonly known as whisk ferns, the other being ''Tmesipteris''. Plants in these two genera were once thought to be d ...
,
marattioid fern Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
s, and
ophioglossoid fern Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only family in the order Ophioglossales, which together with the Psilotales is placed in the sub ...
s. Ferns first appear in the fossil record about 360 million years ago in the late
Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
period, but many of the current families and species did not appear until roughly 145 million years ago in the early
Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
, after flowering plants came to dominate many environments. The fern ''
Osmunda claytoniana ''Claytosmunda'' is a genus of fern. It has only one extant species, ''Claytosmunda claytoniana'' ( synonym ''Osmunda claytoniana''), the interrupted fern, native to Eastern Asia, Eastern United States, and Eastern Canada. The specific epithet ...
'' 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 A biofertilizer is a substance which contains living micro-organisms 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 prim ...
, 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 Bracken (''Pteridium'') is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs ...
(''Pteridium aquilinum'') and water fern (''
Azolla filiculoides ''Azolla filiculoides'' (water fern) is a species of ''Azolla'', native to warm temperate and tropical regions of the Americas which was introduced to Europe, North and sub-Saharan Africa, China, Japan, New Zealand, Australia, the Caribbean and H ...
'') are significant weeds worldwide. Some fern genera, such as ''
Azolla ''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 rese ...
'', can fix nitrogen and make a significant input to the nitrogen nutrition of
rice paddies A paddy field is a flooded field of arable land used for growing semiaquatic crops, most notably rice and taro. It originates from the Neolithic rice-farming cultures of the Yangtze River basin in southern China, associated with pre-Aust ...
. They also play certain roles in folklore.


Description

Extant ferns are herbaceous
perennials A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widel ...
and most lack
wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...
y growth. Their foliage may be
deciduous In the fields of horticulture and Botany, the term ''deciduous'' () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed leaves, usually in the autumn; to the shedding of petals, aft ...
or
evergreen In botany, an evergreen is a plant which has foliage that remains green and functional through more than one growing season. This also pertains to plants that retain their foliage only in warm climates, and contrasts with deciduous plants, which ...
, and some are semi-evergreen depending on the climate. Like the sporophytes of seed plants, those of ferns consist of stems, leaves and roots. Ferns differ from seed plants in reproducing by spores. However, they also differ from spore-producing
bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in ...
s in that, like seed plants, they are
polysporangiophyte Polysporangiophytes, also called polysporangiates or formally Polysporangiophyta, are plants in which the spore-bearing generation (sporophyte) has branching stems (axes) that bear sporangia. The name literally means 'many sporangia plant'. The cl ...
s, their sporophytes branching and producing many sporangia. Also unlike bryophytes, fern sporophytes are free-living and only briefly dependent on the maternal
gametophyte A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...
.


Stems

Fern stems are often referred to as
rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
s, even though they grow underground only in some of the species. Epiphytic species and many of the terrestrial ones have above-ground creeping
stolon In biology, stolons (from Latin '' stolō'', genitive ''stolōnis'' – "branch"), also known as runners, are horizontal connections between organisms. They may be part of the organism, or of its skeleton; typically, animal stolons are external s ...
s (e.g.,
Polypodiaceae Polypodiaceae is a family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family includes around 65 genera and an estimated 1,650 species and is placed in the order Polypodiales, suborder Polypodiineae. A broader ...
), and many groups have above-ground erect semi-woody trunks (e.g.,
Cyatheaceae The Cyatheaceae are a family of ferns, the scaly tree ferns, one of eight families in the order Cyatheales in the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Alternatively, the family may defined much more broadly (Cyatheaceae '' ...
). These can reach up to tall in a few species (e.g., ''
Cyathea brownii ''Sphaeropteris excelsa'', synonym ''Cyathea brownii'', commonly known as the Norfolk tree fern or smooth tree fern, is probably the largest fern species in the world. It is endemic to Norfolk Island, in the Pacific Ocean near Australia and New ...
'' on
Norfolk Island Norfolk Island (, ; Norfuk: ''Norf'k Ailen'') is an external territory of Australia located in the Pacific Ocean between New Zealand and New Caledonia, directly east of Australia's Evans Head and about from Lord Howe Island. Together with ...
and ''
Cyathea medullaris ''Sphaeropteris medullaris'', synonym ''Cyathea medullaris'', commonly known as mamaku or black tree fern, is a large tree fern up to 20 m tall. It is distributed across the south-west Pacific from Fiji to Pitcairn Island. Its other Māori names ...
'' in
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
).


Leaves

The
green Green is the color between cyan and yellow on the visible spectrum. It is evoked by light which has a dominant wavelength of roughly 495570 Nanometre, nm. In subtractive color systems, used in painting and color printing, it is created by ...
,
photosynthetic Photosynthesis is a process used by plants and other organisms to convert light energy into chemical energy that, through cellular respiration, can later be released to fuel the organism's activities. Some of this chemical energy is stored in c ...
part of the plant is technically a
megaphyll In plant anatomy and evolution a microphyll (or lycophyll) is a type of plant leaf with one single, unbranched leaf vein. Plants with microphyll leaves occur early in the fossil record, and few such plants exist today. In the classical concept of ...
and in ferns, it is often referred to as a ''
frond A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...
''. New leaves typically expand by the unrolling of a tight spiral called a crozier or
fiddlehead Fiddleheads or fiddlehead greens are the furled fronds of a young fern, harvested for use as a vegetable. Left on the plant, each fiddlehead would unroll into a new frond (circinate vernation). As fiddleheads are harvested early in the sea ...
into
frond A frond is a large, divided leaf. In both common usage and botanical nomenclature, the leaves of ferns are referred to as fronds and some botanists restrict the term to this group. Other botanists allow the term frond to also apply to the lar ...
s. This uncurling of the leaf is termed
circinate vernation Vernation (from ''vernal'' meaning ''spring'', since that is when leaves spring forth in temperate regions) is the formation of new leaves or fronds. In plant anatomy, it is the arrangement of leaves in a bud. In pine species, new leaves are short ...
. Leaves are divided into two types: sporophylls and tropophylls.
Sporophylls A sporophyll is a leaf that bears sporangia. Both microphylls and megaphylls can be sporophylls. In heterosporous plants, sporophylls (whether they are microphylls or megaphylls) bear either megasporangia and thus are called megasporophylls, or mi ...
produce spores; tropophylls do not. Fern spores are borne in
sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cy ...
which are usually clustered to form sori. In monomorphic ferns, the fertile and sterile leaves looks morphologically the same, and are photosynthesizing in the same way. In hemidimorphic ferns, just a portion of the fertile leaf is different from the sterile leaves. And in dimorphic ferns, also called holomorphic ferns, the two types of leaves are morphologically distinct (
frond dimorphism Frond dimorphism refers to a difference in ferns between the fertile and sterile fronds. Since ferns, unlike flowering plants, bear spores on the leaf blade itself, this may affect the form of the frond itself. In some species of ferns, there is v ...
). The fertile leaves are much narrower than the sterile leaves, and may even have no green tissue at all (e.g.,
Blechnaceae Blechnaceae is a family of ferns in the order Polypodiales, with a cosmopolitan distribution. Its status as a family and the number of genera included have both varied considerably. In the Pteridophyte Phylogeny Group classification of 2016 ( ...
,
Lomariopsidaceae The Lomariopsidaceae is a family of ferns with a largely tropical distribution. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the family is placed in the suborder Polypodiineae (eupolypods I) of the order Polypodiales. ...
). The anatomy of fern leaves can be anywhere from simple to highly divided, or even indeterminate (e.g.
Gleicheniaceae The forked ferns are the family Gleicheniaceae, which includes six genera and about 160 known species. The formerly independent families Dicranopteridaceae and Stromatopteridaceae are generally included in the Gleicheniaceae, whereas the Dipterid ...
, Lygodiaceae). The divided forms are
pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...
, where the leaf segments are completely separated from one other, or pinnatifid (partially pinnate), where the leaf segments are still partially connected. When the fronds are branched more than once, it can also be a combination of the pinnatifid are pinnate shapes. If the leaf blades are divided twice, the plant has bipinnate fronds, and tripinnate fronds if they branch three times, and all the way to tetra- and pentapinnate fronds. In tree ferns, the main stalk that connects the leaf to the stem (known as the stipe), often has multiple leaflets. The leafy structures that grow from the stipe are known as pinnae and are often again divided into smaller pinnules.


Roots

The underground non-photosynthetic structures that take up water and nutrients from
soil Soil, also commonly referred to as earth or dirt, is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life. Some scientific definitions distinguish ''dirt'' from ''soil'' by restricting the former te ...
. They are always
fibrous Fiber or fibre (from la, fibra, links=no) is a natural or artificial substance that is significantly longer than it is wide. Fibers are often used in the manufacture of other materials. The strongest engineering materials often incorporate ...
and structurally are very similar to the roots of seed plants. As in all other
vascular plants Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
, the
sporophyte A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...
is the dominant phase or generation in the life cycle. The
gametophytes A gametophyte () is one of the two alternating multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has one set of chromosomes. The gametophyte is the sex ...
of ferns, however, are very different from those of seed plants. They are free-living and resemble
liverworts The Marchantiophyta () are a division of non-vascular land plants commonly referred to as hepatics or liverworts. Like mosses and hornworts, they have a gametophyte-dominant life cycle, in which cells of the plant carry only a single set of ge ...
, whereas those of seed plants develop within the spore wall and are dependent on the parent sporophyte for their nutrition. A fern gametophyte typically consists of: *
Prothallus A prothallus, or prothallium, (from Latin ''pro'' = forwards and Greek ''θαλλος'' (''thallos'') = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young ...
: A green, photosynthetic structure that is one cell thick, usually heart or kidney shaped, 3–10 mm long and 2–8 mm broad. The prothallus produces gametes by means of: **
Antheridia An antheridium is a haploid structure or organ producing and containing male gametes (called ''antherozoids'' or sperm). The plural form is antheridia, and a structure containing one or more antheridia is called an androecium. Androecium is also t ...
: Small spherical structures that produce
flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their ...
sperm. **
Archegonia An archegonium (pl: archegonia), from the ancient Greek ''ἀρχή'' ("beginning") and ''γόνος'' ("offspring"), is a multicellular structure or organ of the gametophyte phase of certain plants, producing and containing the ovum or female ga ...
: A flask-shaped structure that produces a single egg at the bottom, reached by the sperm by swimming down the neck. *
Rhizoid Rhizoids are protuberances that extend from the lower epidermal cells of bryophytes and algae. They are similar in structure and function to the root hairs of vascular land plants. Similar structures are formed by some fungi. Rhizoids may be unic ...
s:
root In vascular plants, the roots are the organs of a plant that are modified to provide anchorage for the plant and take in water and nutrients into the plant body, which allows plants to grow taller and faster. They are most often below the sur ...
-like structures (not true roots) that consist of single greatly elongated cells, that absorb water and mineral
salts In chemistry, a salt is a chemical compound consisting of an ionic assembly of positively charged cations and negatively charged anions, which results in a compound with no net electric charge. A common example is table salt, with positively cha ...
over the whole structure. Rhizoids anchor the prothallus to the soil.


Taxonomy

Carl Linnaeus Carl Linnaeus (; 23 May 1707 – 10 January 1778), also known after his ennoblement in 1761 as Carl von Linné Blunt (2004), p. 171. (), was a Swedish botanist, zoologist, taxonomist, and physician who formalised binomial nomenclature, the ...
(1753) originally recognized 15 genera of ferns and fern allies, classifying them in class
Cryptogamia A cryptogam (scientific name Cryptogamae) is a plant (in the wide sense of the word) or a plant-like organism that reproduces by spores, without flowers or seeds. The name ''Cryptogamae'' () means "hidden reproduction", referring to the fact ...
in two groups, Filices (e.g. ''
Polypodium ''Polypodium'' is a genus of ferns in the family Polypodiaceae, subfamily Polypodioideae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). The genus is widely distributed throughout the world, with the highest ...
'') and
Musci Mosses are small, non-vascular flowerless plants in the taxonomic division Bryophyta (, ) ''sensu stricto''. Bryophyta (''sensu lato'', Schimp. 1879) may also refer to the parent group bryophytes, which comprise liverworts, mosses, and hornw ...
(mosses). By 1806 this had increased to 38 genera, and has progressively increased since (''see Figure 1''). Ferns were traditionally classified in the
class Class or The Class may refer to: Common uses not otherwise categorized * Class (biology), a taxonomic rank * Class (knowledge representation), a collection of individuals or objects * Class (philosophy), an analytical concept used differentl ...
Filices, and later in a
Division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a method for computing the result of mathematical division Military *Division (military), a formation typically consisting ...
of the Plant Kingdom named
Pteridophyta A pteridophyte is a vascular plant (with xylem and phloem) that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. Ferns, ...
or Filicophyta. Pteridophyta is no longer recognised as a valid
taxon In biology, a taxon (back-formation from ''taxonomy''; plural taxa) is a group of one or more populations of an organism or organisms seen by taxonomists to form a unit. Although neither is required, a taxon is usually known by a particular nam ...
because it is
paraphyletic In taxonomy (general), taxonomy, a group is paraphyletic if it consists of the group's most recent common ancestor, last common ancestor and most of its descendants, excluding a few Monophyly, monophyletic subgroups. The group is said to be pa ...
. The ferns are also referred to as Polypodiophyta or, when treated as a subdivision of
Tracheophyta Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
(vascular plants), Polypodiopsida, although this name sometimes only refers to leptosporangiate ferns. Traditionally, all of the spore producing
vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
s were informally denominated the
pteridophyte A pteridophyte is a vascular plant (with xylem and phloem) that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. Ferns, ...
s, rendering the term synonymous with ferns and
fern allies Fern allies are a diverse group of seedless vascular plants that are not true ferns. Like ferns, a fern ally disperses by shedding spores to initiate an alternation of generations. Classification Originally, three or four groups of plants were ...
. This can be confusing because members of the division Pteridophyta were also denominated pteridophytes (''sensu stricto''). Traditionally, three discrete groups have been denominated ferns: two groups of eusporangiate ferns, the families
Ophioglossaceae Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only family in the order Ophioglossales, which together with the Psilotales is placed in the sub ...
( adder's tongues,
moonwort ''Botrychium'' is a genus of ferns, seedless vascular plants in the family Ophioglossaceae. ''Botrychium'' species are known as moonworts. They are small, with fleshy roots, and reproduce by spores shed into the air. One part of the leaf, the ...
s, and grape ferns) and
Marattiaceae Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
; and the leptosporangiate ferns. The Marattiaceae are a primitive group of tropical ferns with large, fleshy rhizomes and are now thought to be a sibling taxon to the leptosporangiate ferns. Several other groups of species were considered fern allies: the
clubmoss Lycopodiopsida is a class of vascular plants known as lycopods, lycophytes or other terms including the component lyco-. Members of the class are also called clubmosses, firmosses, spikemosses and quillworts. They have dichotomously branching s ...
es,
spikemoss ''Selaginella'' is the sole genus of vascular plants in the family Selaginellaceae, the spikemosses or lesser clubmosses. This family is distinguished from Lycopodiaceae (the clubmosses) by having scale-leaves bearing a ligule and by having ...
es, and quillworts in
Lycopodiophyta The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest ...
; the whisk ferns of
Psilotaceae Psilotaceae is a family of ferns (class Polypodiopsida) consisting of two genera, ''Psilotum'' and ''Tmesipteris'' with about a dozen species. It is the only family in the order Psilotales. Description Once thought to be descendants of early va ...
; and the horsetails of
Equisetaceae Equisetaceae, sometimes called the horsetail family, is the only extant family of the order Equisetales, with one surviving genus, ''Equisetum'', which comprises about twenty species. Evolution and systematics Equisetaceae is the only survivin ...
. Since this grouping is
polyphyletic A polyphyletic group is an assemblage of organisms or other evolving elements that is of mixed evolutionary origin. The term is often applied to groups that share similar features known as homoplasies, which are explained as a result of converg ...
, the term fern allies should be abandoned, except in a historical context. More recent genetic studies demonstrated that the Lycopodiophyta are more distantly related to other
vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
s, having radiated evolutionarily at the base of the vascular plant
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
, while both the whisk ferns and horsetails are as closely related to leptosporangiate ferns as the
ophioglossoid fern Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only family in the order Ophioglossales, which together with the Psilotales is placed in the sub ...
s and
Marattiaceae Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
. In fact, the whisk ferns and ophioglossoid ferns are demonstrably a
clade A clade (), also known as a monophyletic group or natural group, is a group of organisms that are monophyletic – that is, composed of a common ancestor and all its lineal descendants – on a phylogenetic tree. Rather than the English term, ...
, and the
horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Eq ...
s and
Marattiaceae Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
are arguably another clade.


Molecular phylogenetics

Smith et al. (2006) carried out the first higher-level pteridophyte classification published in the
molecular phylogenetic Molecular phylogenetics () is the branch of phylogeny that analyzes genetic, hereditary molecular differences, predominantly in DNA sequences, to gain information on an organism's evolutionary relationships. From these analyses, it is possible to ...
era, and considered the ferns as monilophytes, as follows: *
Division Division or divider may refer to: Mathematics *Division (mathematics), the inverse of multiplication *Division algorithm, a method for computing the result of mathematical division Military *Division (military), a formation typically consisting ...
Tracheophyta Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
(tracheophytes) - vascular plants ** Sub division
Euphyllophytina The euphyllophytes are a clade of plants within the tracheophytes (the vascular plants). The group may be treated as an unranked clade, a division under the name Euphyllophyta or a subdivision under the name Euphyllophytina. The euphyllophytes ar ...
(euphyllophytes) *** Infradivision
Moniliformopses A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except ...
(monilophytes) *** Infradivision
Spermatophyta A spermatophyte (; ), also known as phanerogam (taxon Phanerogamae) or phaenogam (taxon Phaenogamae), is any plant that produces seeds, hence the alternative name seed plant. Spermatophytes are a subset of the embryophytes or land plants. They inc ...
- seed plants, ~260,000 species ** Subdivision
Lycopodiophyta The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest ...
(lycophytes) - less than 1% of extant vascular plants Molecular data, which remain poorly constrained for many parts of the plants' phylogeny, have been supplemented by morphological observations supporting the inclusion of Equisetaceae in the ferns, notably relating to the construction of their sperm and peculiarities of their roots. However, there remained differences of opinion about the placement of the genus ''
Equisetum ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Eq ...
'' (see
Equisetopsida Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like ...
for further discussion). One possible solution was to denominate only the leptosporangiate ferns as "true ferns" while denominating the other three groups as fern allies. In practice, numerous classification schemes have been proposed for ferns and fern allies, and there has been little consensus among them. The leptosporangiate ferns are sometimes called "true ferns". This group includes most plants familiarly known as ferns. Modern research supports older ideas based on morphology that the Osmundaceae diverged early in the evolutionary history of the leptosporangiate ferns; in certain ways this family is intermediate between the eusporangiate ferns and the leptosporangiate ferns. Rai and Graham (2010) broadly supported the primary groups, but queried their relationships, concluding that "at present perhaps the best that can be said about all relationships among the major lineages of monilophytes in current studies is that we do not understand them very well"., p. 1450 Grewe et al. (2013) confirmed the inclusion of horsetails within ferns ''sensu lato'', but also suggested that uncertainties remained in their precise placement. Other classifications have raised Ophioglossales to the rank of a fifth class, separating the whisk ferns and ophioglossoid ferns. One problem with the classification of ferns is that of
cryptic species In biology, a species complex is a group of closely related organisms that are so similar in appearance and other features that the boundaries between them are often unclear. The taxa in the complex may be able to hybridize readily with each oth ...
. A cryptic species is a species that is morphologically similar to another species, but differs genetically in ways that prevent fertile interbreeding. A good example of this is the currently designated species ''
Asplenium trichomanes ''Asplenium trichomanes'', the maidenhair spleenwort, is a small fern in the spleenwort genus ''Asplenium''. It is a widespread and common species, occurring almost worldwide in a variety of rocky habitats. It is a variable fern with several subs ...
'' (maidenhair spleenwort). This is actually a species complex that includes distinct diploid and tetraploid races. There are minor but unclear morphological differences between the two groups, which prefer distinctly differing habitats. In many cases such as this, the species complexes have been separated into separate species, thus raising the total number of species of ferns. Many more cryptic species may be yet to be discovered and designated.


Phylogeny

The ferns are related to other higher order taxa as shown in the following cladogram:


Nomenclature and subdivision

The classification of Smith et al. (2006) treated ferns as four classes: *
Equisetopsida Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like ...
(Sphenopsida) 1 order,
Equisetales Equisetales is an order of subclass Equisetidae with only one living family, Equisetaceae, containing the genus ''Equisetum'' (horsetails). Classification In the molecular phylogenetic classification of Smith et al. in 2006, Equisetales, in its ...
(
Horsetail ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Eq ...
s) ~ 15 species *
Psilotopsida Ophioglossidae is one of the four subclasses of Polypodiopsida (ferns). This subclass consists of the ferns commonly known as whisk ferns, grape ferns, adder's-tongues and moonworts. It is equivalent to the class Psilotopsida in previous treatm ...
2 orders (
whisk ferns ''Psilotum'' is a genus of fern-like vascular plants. It is one of two Genus, genera in the Family (biology), family Psilotaceae commonly known as whisk ferns, the other being ''Tmesipteris''. Plants in these two genera were once thought to be d ...
and
ophioglossoid fern Ophioglossaceae, the adder's-tongue family, is a small family of ferns. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), it is the only family in the order Ophioglossales, which together with the Psilotales is placed in the sub ...
s) ~92 species *
Marattiopsida Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
1 order,
Marattiales Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
~ 150 species *
Polypodiopsida A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of vascular plants (plants with xylem and phloem) that reproduce via spores and have neither seeds nor flowers. The polypodiophytes include all living pteridophytes except th ...
(Filicopsida) 7 orders (
leptosporangiate fern The Polypodiidae, commonly called leptosporangiate ferns, formerly Leptosporangiatae, are one of four subclasses of ferns, and the largest of these, being the largest group of living ferns, including some 11,000 species worldwide. The group has ...
s) ~ 9,000 species In addition they defined 11 orders and 37 families. That system was a consensus of a number of studies, and was further refined. The phylogenetic relationships are shown in the following
cladogram A cladogram (from Greek ''clados'' "branch" and ''gramma'' "character") is a diagram used in cladistics to show relations among organisms. A cladogram is not, however, an evolutionary tree because it does not show how ancestors are related to d ...
(to the level of orders). This division into four major clades was then confirmed using
morphology Morphology, from the Greek and meaning "study of shape", may refer to: Disciplines * Morphology (archaeology), study of the shapes or forms of artifacts * Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies ...
alone. Subsequently,
Chase Chase or CHASE may refer to: Businesses * Chase Bank, a national bank based in New York City, New York * Chase Aircraft (1943–1954), a defunct American aircraft manufacturing company * Chase Coaches, a defunct bus operator in England * Chase Co ...
and Reveal considered both lycopods and ferns as subclasses of a class Equisetopsida (
Embryophyta The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes () have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as siste ...
) encompassing all land plants. This is referred to as
Equisetopsida Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like ...
''
sensu lato ''Sensu'' is a Latin word meaning "in the sense of". It is used in a number of fields including biology, geology, linguistics, semiotics, and law. Commonly it refers to how strictly or loosely an expression is used in describing any particular co ...
'' to distinguish it from the narrower use to refer to horsetails alone,
Equisetopsida Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like ...
''sensu stricto''. They placed the lycopods into subclass Lycopodiidae and the ferns, keeping the term monilophytes, into five subclasses, Equisetidae, Ophioglossidae, Psilotidae, Marattiidae and Polypodiidae, by dividing Smith's Psilotopsida into its two orders and elevating them to subclass (Ophioglossidae and Psilotidae). Christenhusz et al. (2011) followed this use of subclasses but recombined Smith's Psilotopsida as Ophioglossidae, giving four subclasses of ferns again. Christenhusz and
Chase Chase or CHASE may refer to: Businesses * Chase Bank, a national bank based in New York City, New York * Chase Aircraft (1943–1954), a defunct American aircraft manufacturing company * Chase Coaches, a defunct bus operator in England * Chase Co ...
(2014) developed a new classification of ferns and lycopods. They used the term Polypodiophyta for the ferns, subdivided like Smith et al. into four groups (shown with equivalents in the Smith system), with 21 families, approximately 212 genera and 10,535 species; *
Equisetidae Equisetidae is one of the four subclasses of Polypodiopsida (ferns), a group of vascular plants with a fossil record going back to the Devonian. They are commonly known as horsetails. They typically grow in wet areas, with whorls of needle-like ...
(=Equisetopsida) -
monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...
(Equisetales,
Equisetaceae Equisetaceae, sometimes called the horsetail family, is the only extant family of the order Equisetales, with one surviving genus, ''Equisetum'', which comprises about twenty species. Evolution and systematics Equisetaceae is the only survivin ...
, ''
Equisetum ''Equisetum'' (; horsetail, snake grass, puzzlegrass) is the only living genus in Equisetaceae, a family of ferns, which reproduce by spores rather than seeds. ''Equisetum'' is a "living fossil", the only living genus of the entire subclass Eq ...
'') horsetails ~ 20 species) *
Ophioglossidae Ophioglossidae is one of the four subclasses of Polypodiopsida (ferns). This subclass consists of the ferns commonly known as whisk ferns, grape ferns, adder's-tongues and moonworts. It is equivalent to the class Psilotopsida in previous treatm ...
(=Psilotopsida) - 2 monotypic orders ~ 92 species *
Marattiidae Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
(=Marattiopsida) - 1 monotypic order (Marattiales,
Marattiaceae Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about ...
, 2 subfamilies) ~ 130 species *
Polypodiidae Polypodiidae may refer to: * Polypodiidae (cnidarians), a zoological family that only includes ''Polypodium hydriforme'', a cnidarian parasite of fish eggs *Polypodiidae (plant), a botanical subclass of Equisetopsida sensu lato that includes the le ...
(=Polypodiopsida) - 7 orders This was a considerable reduction in the number of families from the 37 in the system of Smith et al., since the approach was more that of
lumping Lumpers and splitters are opposing factions in any discipline that has to place individual examples into rigorously defined categories. The lumper–splitter problem occurs when there is the desire to create classifications and assign examples t ...
rather than splitting. For instance a number of families were reduced to subfamilies. Subsequently, a consensus group was formed, the
Pteridophyte Phylogeny Group The Pteridophyte Phylogeny Group, or PPG, is an informal international group of systematic botanists who collaborate to establish a consensus on the classification of pteridophytes (lycophytes and ferns) that reflects knowledge about plant relation ...
(PPG), analogous to the
Angiosperm Phylogeny Group The Angiosperm Phylogeny Group (APG) is an informal international group of systematic botanists who collaborate to establish a consensus on the taxonomy of flowering plants (angiosperms) that reflects new knowledge about plant relationships disco ...
, publishing their first complete classification in November 2016. They recognise ferns as a class, the Polypodiopsida, with four subclasses as described by Christenhusz and Chase, and which are phylogenetically related as in this cladogram: In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), the Polypodiopsida consist of four subclasses, 11 orders, 48 families, 319 genera, and an estimated 10,578 species. Thus Polypodiopsida in the broad sense (''sensu lato'') as used by the PPG (Polypodiopsida ''sensu'' PPG I) needs to be distinguished from the narrower usage (''sensu stricto'') of Smith et al. (Polypodiopsida ''sensu'' Smith et al.) Classification of ferns remains unresolved and controversial with competing viewpoints (
splitting vs lumping Lumpers and splitters are opposing factions in any Discipline (academia), discipline that has to place individual examples into rigorously defined Categorization, categories. The lumper–splitter problem occurs when there is the desire to create ...
) between the systems of the PPG on the one hand and Christenhusz and Chase on the other, respectively. In 2018, Christenhusz and Chase explicitly argued against recognizing as many genera as PPG I.


Evolution and biogeography

Fern-like taxa (''
Wattieza ''Wattieza'' was a genus of prehistoric trees that existed in the mid-Devonian that belong to the cladoxylopsids, close relatives of the modern ferns and horsetails. The 2005 (publicly revealed in 2007) discovery in Schoharie County, New Yor ...
'') first appear in the fossil record in the middle
Devonian The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, whe ...
period, ca. 390  Mya. By the
Triassic The Triassic ( ) is a geologic period and system which spans 50.6 million years from the end of the Permian Period 251.902 million years ago ( Mya), to the beginning of the Jurassic Period 201.36 Mya. The Triassic is the first and shortest period ...
, the first evidence of ferns related to several modern families appeared. The great fern radiation occurred in the late
Cretaceous The Cretaceous ( ) is a geological period that lasted from about 145 to 66 million years ago (Mya). It is the third and final period of the Mesozoic Era, as well as the longest. At around 79 million years, it is the longest geological period of th ...
, when many modern families of ferns first appeared. Ferns evolved to cope with low-light conditions present under the canopy of angiosperms. Remarkably, the photoreceptor neochrome in the two orders Cyatheales and Polypodiales, integral to their adaptation to low-light conditions, was obtained via
horizontal gene transfer Horizontal gene transfer (HGT) or lateral gene transfer (LGT) is the movement of genetic material between Unicellular organism, unicellular and/or multicellular organisms other than by the ("vertical") transmission of DNA from parent to offsprin ...
from
hornworts Hornworts are a group of non-vascular Embryophytes (land plants) constituting the division Anthocerotophyta (). The common name refers to the elongated horn-like structure, which is the sporophyte. As in mosses and liverworts, hornworts have a ...
, a
bryophyte The Bryophyta s.l. are a proposed taxonomic division containing three groups of non-vascular land plants (embryophytes): the liverworts, hornworts and mosses. Bryophyta s.s. consists of the mosses only. They are characteristically limited in ...
lineage. Due to the very large genome seen in most ferns, it was suspected they might had gone through whole genome duplications, but
DNA sequencing DNA sequencing is the process of determining the nucleic acid sequence – the order of nucleotides in DNA. It includes any method or technology that is used to determine the order of the four bases: adenine, guanine, cytosine, and thymine. Th ...
has shown that their genome size is caused by the accumulation of mobile DNA like
transposons A transposable element (TE, transposon, or jumping gene) is a nucleic acid sequence in DNA that can change its position within a genome, sometimes creating or reversing mutations and altering the cell's genetic identity and genome size. Transpo ...
and other genetic elements that infect genomes and get copied over and over again.


Distribution and habitat

Ferns are widespread in their distribution, with the greatest richness in the tropics and least in arctic areas. The greatest diversity occurs in tropical rainforests. New Zealand, for which the fern is a symbol, has about 230 species, distributed throughout the country.


Ecology

Fern species live in a wide variety of
habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...
s, from remote
mountain A mountain is an elevated portion of the Earth's crust, generally with steep sides that show significant exposed bedrock. Although definitions vary, a mountain may differ from a plateau in having a limited Summit (topography), summit area, and ...
elevations, to dry
desert A desert is a barren area of landscape where little precipitation occurs and, consequently, living conditions are hostile for plant and animal life. The lack of vegetation exposes the unprotected surface of the ground to denudation. About on ...
rock faces, bodies of water or open fields. Ferns in general may be thought of as largely being specialists in marginal habitats, often succeeding in places where various environmental factors limit the success of
flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
s. Some ferns are among the world's most serious weed species, including the
bracken Bracken (''Pteridium'') is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs ...
fern growing in the Scottish highlands, or the mosquito fern (''
Azolla ''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 rese ...
'') growing in tropical lakes, both species forming large aggressively spreading colonies. There are four particular types of habitats that ferns are found in: moist, shady
forest A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' ...
s; crevices in rock faces, especially when sheltered from the full sun; acid wetlands including
bog A bog or bogland is a wetland that accumulates peat as a deposit of dead plant materials often mosses, typically sphagnum moss. It is one of the four main types of wetlands. Other names for bogs include mire, mosses, quagmire, and muskeg; a ...
s and
swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...
s; and tropical
tree In botany, a tree is a perennial plant with an elongated stem, or trunk, usually supporting branches and leaves. In some usages, the definition of a tree may be narrower, including only woody plants with secondary growth, plants that are ...
s, where many species are
epiphyte An epiphyte is an organism that grows on the surface of a plant and derives its moisture and nutrients from the air, rain, water (in marine environments) or from debris accumulating around it. The plants on which epiphytes grow are called phoroph ...
s (something like a quarter to a third of all fern species). Especially the epiphytic ferns have turned out to be hosts of a huge diversity of invertebrates. It is assumed that
bird's-nest fern Bird's-nest fern is a common name applied to several related species of epiphytic ferns in the genus ''Asplenium ''Asplenium'' is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other auth ...
s alone contain up to half the invertebrate biomass within a hectare of
rainforest Rainforests are characterized by a closed and continuous tree canopy, moisture-dependent vegetation, the presence of epiphytes and lianas and the absence of wildfire. Rainforest can be classified as tropical rainforest or temperate rainfores ...
canopy. Many ferns depend on associations with
mycorrhizal   A mycorrhiza (from Greek μύκης ', "fungus", and ῥίζα ', "root"; pl. mycorrhizae, mycorrhiza or mycorrhizas) is a symbiotic association between a fungus and a plant. The term mycorrhiza refers to the role of the fungus in the plan ...
fungi. Many ferns grow only within specific pH ranges; for instance, the climbing fern ('' Lygodium palmatum'') of eastern
North America North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
will grow only in moist, intensely
acid In computer science, ACID ( atomicity, consistency, isolation, durability) is a set of properties of database transactions intended to guarantee data validity despite errors, power failures, and other mishaps. In the context of databases, a sequ ...
soils, while the bulblet bladder fern (''
Cystopteris bulbifera ''Cystopteris bulbifera'', with the common name bulblet fern, bulblet bladderfern, or bulblet fragile fern is a fern in the family Cystopteridaceae. Distribution The fern is native to eastern Canada, the Midwestern and Eastern United States, an ...
''), with an overlapping range, is found only on
limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms whe ...
. The spores are rich in
lipid Lipids are a broad group of naturally-occurring molecules which includes fats, waxes, sterols, fat-soluble vitamins (such as vitamins A, D, E and K), monoglycerides, diglycerides, phospholipids, and others. The functions of lipids include ...
s,
protein Proteins are large biomolecules and macromolecules that comprise one or more long chains of amino acid residues. Proteins perform a vast array of functions within organisms, including catalysing metabolic reactions, DNA replication, respo ...
and
calories The calorie is a unit of energy. For historical reasons, two main definitions of "calorie" are in wide use. The large calorie, food calorie, or kilogram calorie was originally defined as the amount of heat needed to raise the temperature of on ...
, so some vertebrates eat these. The
European woodmouse The wood mouse (''Apodemus sylvaticus'') is a Muridae, murid rodent native to Europe and northwestern Africa. It is closely related to the yellow-necked mouse (''Apodemus flavicollis'') but differs in that it has no band of yellow fur around the ...
(''Apodemus sylvaticus'') has been found to eat the spores of ''
Culcita macrocarpa ''Culcita macrocarpa'', the woolly tree fern, is a species of fern in the family Culcitaceae native to Macaronesia and parts of the Iberian Peninsula, where it might have been introduced. Description ''Culcita macrocarpa'' is a large plant tha ...
'', and the
bullfinch Bullfinch is a name given to two groups of passerine birds. True bullfinches The true bullfinches are thick-billed finches in the passerine family Fringillidae. They comprise the genus ''Pyrrhula''. These birds are restricted to the Old World, an ...
(''Pyrrhula murina'') and the
New Zealand lesser short-tailed bat The New Zealand lesser short-tailed bat (''Mystacina tuberculata'') is a small-sized omnivorous mammal endemic to the islands of New Zealand. It is one of two extant and three overall terrestrial mammal species unique to New Zealand. The NZ lesse ...
(''Mystacina tuberculata'') also eat fern spores.


Life cycle

Ferns are
vascular plant Vascular plants (), also called tracheophytes () or collectively Tracheophyta (), form a large group of land plants ( accepted known species) that have lignified tissues (the xylem) for conducting water and minerals throughout the plant. They al ...
s differing from
lycophyte The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest ...
s by having true
leaves A leaf (plural, : leaves) is any of the principal appendages of a vascular plant plant stem, stem, usually borne laterally aboveground and specialized for photosynthesis. Leaves are collectively called foliage, as in "autumn foliage", wh ...
(megaphylls), which are often
pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...
. They differ from
seed plant A spermatophyte (; ), also known as phanerogam (taxon Phanerogamae) or phaenogam (taxon Phaenogamae), is any plant that produces seeds, hence the alternative name seed plant. Spermatophytes are a subset of the embryophytes or land plants. They inc ...
s (
gymnosperm The gymnosperms ( lit. revealed seeds) are a group of seed-producing plants that includes conifers, cycads, ''Ginkgo'', and gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in el, γυμνό ...
s and
angiosperm Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
s) in reproducing by means of spores and lacking
flower A flower, sometimes known as a bloom or blossom, is the reproductive structure found in flowering plants (plants of the division Angiospermae). The biological function of a flower is to facilitate reproduction, usually by providing a mechani ...
s and
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
s. Like all
land plants The Embryophyta (), or land plants, are the most familiar group of green plants that comprise vegetation on Earth. Embryophytes () have a common ancestor with green algae, having emerged within the Phragmoplastophyta clade of green algae as siste ...
, they have a
life cycle Life cycle, life-cycle, or lifecycle may refer to: Science and academia *Biological life cycle, the sequence of life stages that an organism undergoes from birth to reproduction ending with the production of the offspring *Life-cycle hypothesis, ...
referred to as
alternation of generations Alternation of generations (also known as metagenesis or heterogenesis) is the predominant type of Biological life cycle, life cycle in plants and algae. It consists of a Multicellular organism, multicellular haploid sexual phase, the gametophy ...
, characterized by alternating
diploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...
sporophytic A sporophyte () is the diploid multicellular stage in the life cycle of a plant or alga which produces asexual spores. This stage alternates with a multicellular haploid gametophyte phase. Life cycle The sporophyte develops from the zygote pr ...
and
haploid Ploidy () is the number of complete sets of chromosomes in a cell, and hence the number of possible alleles for autosomal and pseudoautosomal genes. Sets of chromosomes refer to the number of maternal and paternal chromosome copies, respectively ...
gametophytic A gametophyte () is one of the two alternation of generations, alternating multicellular organism, multicellular phases in the life cycles of plants and algae. It is a haploid multicellular organism that develops from a haploid spore that has on ...
phases. The diploid sporophyte has 2''n'' paired
chromosome A chromosome is a long DNA molecule with part or all of the genetic material of an organism. In most chromosomes the very long thin DNA fibers are coated with packaging proteins; in eukaryotic cells the most important of these proteins are ...
s, where ''n'' varies from species to species. The haploid gametophyte has ''n'' unpaired chromosomes, i.e. half the number of the sporophyte. The gametophyte of ferns is a free-living organism, whereas the gametophyte of the gymnosperms and angiosperms is dependent on the sporophyte. The life cycle of a typical fern proceeds as follows: # A diploid sporophyte phase produces haploid
spore In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...
s by
meiosis Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately resu ...
(a process of cell division which reduces the number of chromosomes by a half). # A spore grows into a free-living haploid gametophyte by
mitosis In cell biology, mitosis () is a part of the cell cycle in which replicated chromosomes are separated into two new nuclei. Cell division by mitosis gives rise to genetically identical cells in which the total number of chromosomes is mainta ...
(a process of cell division which maintains the number of chromosomes). The gametophyte typically consists of a photosynthetic
prothallus A prothallus, or prothallium, (from Latin ''pro'' = forwards and Greek ''θαλλος'' (''thallos'') = twig) is usually the gametophyte stage in the life of a fern or other pteridophyte. Occasionally the term is also used to describe the young ...
. # The gametophyte produces
gametes A gamete (; , ultimately ) is a haploid cell that fuses with another haploid cell during fertilization in organisms that reproduce sexually. Gametes are an organism's reproductive cells, also referred to as sex cells. In species that produce t ...
(often both
sperm Sperm is the male reproductive cell, or gamete, in anisogamous forms of sexual reproduction (forms in which there is a larger, female reproductive cell and a smaller, male one). Animals produce motile sperm with a tail known as a flagellum, whi ...
and
egg An egg is an organic vessel grown by an animal to carry a possibly fertilized egg cell (a zygote) and to incubate from it an embryo within the egg until the embryo has become an animal fetus that can survive on its own, at which point the a ...
s on the same prothallus) by mitosis. # A mobile,
flagellate A flagellate is a cell or organism with one or more whip-like appendages called flagella. The word ''flagellate'' also describes a particular construction (or level of organization) characteristic of many prokaryotes and eukaryotes and their ...
sperm fertilizes an egg that remains attached to the prothallus. # The fertilized egg is now a diploid
zygote A zygote (, ) is a eukaryotic cell formed by a fertilization event between two gametes. The zygote's genome is a combination of the DNA in each gamete, and contains all of the genetic information of a new individual organism. In multicellula ...
and grows by mitosis into a diploid sporophyte (the typical fern plant).


Uses

Ferns are not as important economically as seed plants, but have considerable importance in some societies. Some ferns are used for food, including the fiddleheads of ''Pteridium aquilinum'' (
bracken Bracken (''Pteridium'') is a genus of large, coarse ferns in the family Dennstaedtiaceae. Ferns (Pteridophyta) are vascular plants that have alternating generations, large plants that produce spores and small plants that produce sex cells (eggs ...
), ''Matteuccia struthiopteris'' (
ostrich fern ''Matteuccia'' is a genus of ferns with one species: ''Matteuccia struthiopteris'' (common names ostrich fern, fiddlehead fern, or shuttlecock fern). The species epithet ''struthiopteris'' comes from Ancient Greek words () "ostrich" and () "fer ...
), and ''Osmundastrum cinnamomeum'' (
cinnamon fern ''Osmundastrum'' is genus of leptosporangiate ferns in the family Osmundaceae with one living species, ''Osmundastrum cinnamomeum'', the cinnamon fern. It is native to the Americas and eastern Asia, growing in swamps, bogs and moist woodlands. I ...
). ''
Diplazium esculentum ''Diplazium esculentum'', the vegetable fern, is an edible fern found throughout Asia and Oceania. It is probably the most commonly consumed fern. The genus ''Diplazium'' is in the family Athyriaceae, in the eupolypods II clade of the order Pol ...
'' is also used in the tropics (for example in ''budu pakis'', a traditional dish of
Brunei Brunei ( , ), formally Brunei Darussalam ( ms, Negara Brunei Darussalam, Jawi alphabet, Jawi: , ), is a country located on the north coast of the island of Borneo in Southeast Asia. Apart from its South China Sea coast, it is completely sur ...
) as food. Tubers from the "para", ''
Ptisana salicina ''Ptisana salicina'', or king fern, is a species of fern native to Norfolk Island, New Zealand and the South Pacific. Large and robust with a distinctive tropical appearance, it has fronds up to 5 metres (16 feet +/-) tall that arise from a star ...
'' (king fern) are a traditional food in
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
and the South Pacific. Fern tubers were used for food 30,000 years ago in Europe. Fern tubers were used by the
Guanches The Guanches were the indigenous inhabitants of the Canary Islands in the Atlantic Ocean some west of Africa. It is believed that they may have arrived on the archipelago some time in the first millennium BCE. The Guanches were the only nativ ...
to make
gofio Gofio is a sort of Canarian flour made from roasted grains (typically wheat or certain varieties of maize) or other starchy plants (e.g. beans and, historically, fern root), some varieties containing a little added salt. Gofio has been an im ...
in the
Canary Islands The Canary Islands (; es, Canarias, ), also known informally as the Canaries, are a Spanish autonomous community and archipelago in the Atlantic Ocean, in Macaronesia. At their closest point to the African mainland, they are west of Morocc ...
. Ferns are generally not known to be poisonous to humans.
Licorice fern ''Polypodium glycyrrhiza'', commonly known as licorice fern, many-footed fern, and sweet root, is a summer deciduous fern native to western North America, where it is found in shaded, damp locations. Spores are located in rounded sori on the un ...
rhizome In botany and dendrology, a rhizome (; , ) is a modified subterranean plant stem that sends out roots and shoots from its nodes. Rhizomes are also called creeping rootstalks or just rootstalks. Rhizomes develop from axillary buds and grow hori ...
s were chewed by the natives of the
Pacific Northwest The Pacific Northwest (sometimes Cascadia, or simply abbreviated as PNW) is a geographic region in western North America bounded by its coastal waters of the Pacific Ocean to the west and, loosely, by the Rocky Mountains to the east. Though ...
for their flavor. Ferns of the genus ''Azolla'', commonly known as water fern or mosquito ferns are very small, floating plants that do not resemble ferns. The mosquito ferns are used as a biological fertilizer in the rice paddies of southeast Asia, taking advantage of their ability to fix nitrogen from the air into compounds that can then be used by other plants. Ferns have proved resistant to phytophagous insects. The gene that express the protein Tma12 in an edible fern, ''
Tectaria macrodonta ''Tectaria'' is a genus of fern in the family Tectariaceae, according to the Pteridophyte Phylogeny Group classification of 2016 (PPG I). Halberd fern is a common name for species in this genus. Species , the ''Checklist of Ferns and Lycophyte ...
'', has been transferred to cotton plants, which became resistant to
whitefly Whiteflies are Hemipterans that typically feed on the undersides of plant leaves. They comprise the family Aleyrodidae, the only family in the superfamily Aleyrodoidea. More than 1550 species have been described. Description and taxonomy The A ...
infestations. Many ferns are grown in
horticulture Horticulture is the branch of agriculture that deals with the art, science, technology, and business of plant cultivation. It includes the cultivation of fruits, vegetables, nuts, seeds, herbs, sprouts, mushrooms, algae, flowers, seaweeds and no ...
as landscape plants, for cut foliage and as
houseplant A houseplant, sometimes known as a pot plant, potted plant, or an indoor plant, is an ornamental plant that is grown indoors. As such, they are found in places like residences and offices, mainly for decorative purposes. Common houseplants are us ...
s, especially the Boston fern (''
Nephrolepis exaltata ''Nephrolepis exaltata'', known as the sword fern or Boston fern, is a species of fern in the family Lomariopsidaceae (sometimes treated in the families Davalliaceae or Oleandraceae, or in its own family, Nephrolepidaceae). It is native to the A ...
'') and other members of the genus ''
Nephrolepis ''Nephrolepis'' is a genus of about 30 species of ferns. It is the only genus in the family Nephrolepidaceae, placed in the suborder Aspleniineae (eupolypods I) of the order Polypodiales in the Pteridophyte Phylogeny Group classification of 2016 ...
''. The
bird's nest fern Bird's-nest fern is a common name applied to several related species of epiphyte, epiphytic ferns in the genus ''Asplenium''. They grow in a tight, nest-like clump with a lingulate leaf rosette. Species known as bird's nest fern include: *''Aspleni ...
(''Asplenium nidus'') is also popular, as are the
staghorn fern ''Platycerium'' is a genus of about 18 fern species in the polypod family, Polypodiaceae. Ferns in this genus are widely known as staghorn or elkhorn ferns due to their uniquely shaped fronds. This genus is epiphytic and is native to tropical and ...
s (genus ''Platycerium''). Perennial (also known as hardy) ferns planted in gardens in the northern hemisphere also have a considerable following. Several ferns, such as bracken and ''Azolla'' species are noxious
weed A weed is a plant considered undesirable in a particular situation, "a plant in the wrong place", or a plant growing where it is not wanted.Harlan, J. R., & deWet, J. M. (1965). Some thoughts about weeds. ''Economic botany'', ''19''(1), 16-24. ...
s or
invasive species An invasive species otherwise known as an alien is an introduced organism that becomes overpopulated and harms its new environment. Although most introduced species are neutral or beneficial with respect to other species, invasive species ad ...
. Further examples include Japanese climbing fern (''
Lygodium japonicum ''Lygodium japonicum'' is a species of fern that is known by the common names vine-like fern and Japanese climbing fern. It is native to eastern Asia, including Taiwan, Japan, Korea, southeastern Asia, and India, and eastern Australia. The fern ...
''), sensitive fern (''Onoclea sensibilis'') and Giant water fern (''
Salvinia molesta ''Salvinia molesta'', commonly known as giant salvinia, or as kariba weed after it infested a large portion of Lake Kariba between Zimbabwe and Zambia, is an aquatic fern, native to south-eastern Brazil. It is a free-floating plant that does n ...
''), one of the world's worst aquatic weeds. The important fossil fuel
coal Coal is a combustible black or brownish-black sedimentary rock, formed as rock strata called coal seams. Coal is mostly carbon with variable amounts of other elements, chiefly hydrogen, sulfur, oxygen, and nitrogen. Coal is formed when dea ...
consists of the remains of primitive plants, including ferns. Ferns have been studied and found to be useful in the removal of heavy metals, especially arsenic, from the soil. Other ferns with some economic significance include: * ''
Dryopteris filix-mas ''Dryopteris filix-mas'', the male fern, is a common fern of the temperate Northern Hemisphere, native to much of Europe, Asia, and North America. It favours damp shaded areas in the understory of woodlands, but also shady places on hedge-banks, ...
'' (male fern), used as a
vermifuge Anthelmintics or antihelminthics are a group of antiparasitic drugs that expel parasitic worms (helminths) and other internal parasites from the body by either stunning or killing them and without causing significant damage to the host. They may a ...
, and formerly in the
US Pharmacopeia The ''United States Pharmacopeia'' (''USP'') is a pharmacopeia (compendium of drug information) for the United States published annually by the United States Pharmacopeial Convention (usually also called the USP), a nonprofit organization that ...
; also, this fern accidentally sprouting in a bottle resulted in
Nathaniel Bagshaw Ward Nathaniel Bagshaw Ward (1791 – 4 June 1868 in St Leonard's, Sussex) was an English doctor who popularised a case for growing and transporting plants which was called the Wardian case. Biography Ward was born in London to Stephen Smith Wa ...
's 1829 invention of the terrarium or
Wardian case The Wardian case was an early type of terrarium, a sealed protective container for plants. It found great use in the 19th century in protecting foreign plants imported to Europe from overseas, the great majority of which had previously died from ...
* ''
Rumohra adiantiformis ''Rumohra adiantiformis'', the leather fern or leatherleaf fern,Gilman, E. F''Rumohra adiantiformis''.Fact Sheet FPS-515. University of Florida Cooperative Extension, IFAS. 1999. is a species of fern in the wood fern family Dryopteridaceae. It ha ...
'' (floral fern), extensively used in the
florist Floristry is the production, commerce, and trade in flowers. It encompasses flower care and handling, floral design and arrangement, merchandising, production, display and flower delivery. Wholesale florists sell bulk flowers and related sup ...
trade * ''
Microsorum pteropus ''Leptochilus pteropus'', synonym ''Microsorum pteropus'', commonly known as Java fern after the Indonesian island of Java, can be found in Malaysia, Thailand, Northeast India and some regions of China. It is a highly variable plant with several ...
'' (Java fern), one of the most popular freshwater
aquarium plants An aquarium (plural: ''aquariums'' or ''aquaria'') is a vivarium of any size having at least one transparent side in which aquatic plants or animals are kept and displayed. Fishkeepers use aquaria to keep fish, invertebrates, amphibians, aqu ...
. * ''
Osmunda regalis ''Osmunda regalis'', or royal fern, is a species of deciduous fern, native to Europe, Africa and Asia, growing in woodland bogs and on the banks of streams. The species is sometimes known as flowering fern due to the appearance of its fertile fr ...
'' (royal fern) and ''
Osmunda cinnamomea ''Osmundastrum'' is genus of leptosporangiate ferns in the family Osmundaceae with one living species, ''Osmundastrum cinnamomeum'', the cinnamon fern. It is native to the Americas and eastern Asia, growing in swamps, bogs and moist woodlands. I ...
'' (cinnamon fern), the root fiber being used horticulturally; the fiddleheads of ''O. cinnamomea'' are also used as a cooked vegetable * ''
Matteuccia struthiopteris ''Matteuccia'' is a genus of ferns with one species: ''Matteuccia struthiopteris'' (common names ostrich fern, fiddlehead fern, or shuttlecock fern). The species epithet ''struthiopteris'' comes from Ancient Greek words () "ostrich" and () "fer ...
'' (ostrich fern), the fiddleheads used as a cooked vegetable in North America * ''
Pteridium aquilinum ''Pteridium aquilinum'' (bracken, brake or common bracken), also known as eagle fern, is a species of fern occurring in temperate and subtropical regions in both hemispheres. Originally native to Eurasia and North America, the extreme lightness o ...
'' and ''
Pteridium esculentum ''Pteridium esculentum'', commonly known as bracken fern, Austral bracken or simply bracken, is a species of the bracken genus native to a number of countries in the Southern Hemisphere. Esculentum means edible. First described as ''Pteris escul ...
'' (bracken), the fiddleheads used as a cooked vegetable in Japan and are believed to be responsible for the high rate of stomach cancer in Japan. It is also one of the world's most important agricultural weeds, especially in the British highlands, and often poisons cattle and horses. * ''
Diplazium esculentum ''Diplazium esculentum'', the vegetable fern, is an edible fern found throughout Asia and Oceania. It is probably the most commonly consumed fern. The genus ''Diplazium'' is in the family Athyriaceae, in the eupolypods II clade of the order Pol ...
'' (vegetable fern), a source of food for some societies * ''
Pteris vittata ''Pteris vittata'', commonly known variously as the Chinese brake, Chinese ladder brake, or simply ladder brake, is a fern species in the Pteridoideae subfamily of the Pteridaceae. It is indigenous to Asia, southern Europe, tropical Africa and Au ...
'' (brake fern), used to absorb
arsenic Arsenic is a chemical element with the symbol As and atomic number 33. Arsenic occurs in many minerals, usually in combination with sulfur and metals, but also as a pure elemental crystal. Arsenic is a metalloid. It has various allotropes, but ...
from the soil * ''
Polypodium glycyrrhiza ''Polypodium glycyrrhiza'', commonly known as licorice fern, many-footed fern, and sweet root, is a summer deciduous fern native to western North America, where it is found in shaded, damp locations. Spores are located in rounded sori on the u ...
'' (licorice fern), roots chewed for their pleasant flavor *
Tree fern The tree ferns are arborescent (tree-like) ferns that grow with a trunk elevating the fronds above ground level, making them trees. Many extant tree ferns are members of the order Cyatheales, to which belong the families Cyatheaceae (scaly tree ...
s, used as building material in some tropical areas * ''
Cyathea cooperi ''Sphaeropteris cooperi'', synonym ''Cyathea cooperi'', also known as lacy tree fern, scaly tree fern, or Cooper's tree fern, is a tree fern native to Australia, in New South Wales and Queensland. Description ''Sphaeropteris cooperi'' is a ...
'' (Australian tree fern), an important invasive species in Hawaii * ''
Ceratopteris richardii ''Ceratopteris richardii'' is a fern species belonging to the genus ''Ceratopteris'', one of only two genera of the subfamily Parkerioideae of the family Pteridaceae. It is one of several genera of ferns adapted to an aquatic existence. ''C. ri ...
'', a model plant for teaching and research, often called C-fern


Culture


Pteridologist

The study of ferns and other pteridophytes is called pteridology. A pteridologist is a specialist in the study of pteridophytes in a broader sense that includes the more distantly related
lycophyte The lycophytes, when broadly circumscribed, are a vascular plant (tracheophyte) subgroup of the kingdom Plantae. They are sometimes placed in a division Lycopodiophyta or Lycophyta or in a subdivision Lycopodiophytina. They are one of the oldest ...
s.


Pteridomania

Pteridomania Pteridomania or fern fever was a Victorian craze for ferns. Decorative arts of the period presented the fern motif in pottery, glass, metal, textiles, wood, printed paper, and sculpture, with ferns "appearing on everything from christening ...
is a term for the
Victorian era In the history of the United Kingdom and the British Empire, the Victorian era was the period of Queen Victoria's reign, from 20 June 1837 until her death on 22 January 1901. The era followed the Georgian period and preceded the Edwardia ...
craze of fern
collecting The hobby of collecting includes seeking, locating, acquiring, organizing, cataloging, displaying, storing, and maintaining items that are of interest to an individual ''collector''. Collections differ in a wide variety of respects, most obvio ...
and fern motifs in
decorative art ] The decorative arts are arts or crafts whose object is the design and manufacture of objects that are both beautiful and functional. It includes most of the arts making objects for the interiors of buildings, and interior design, but not usual ...
including
pottery Pottery is the process and the products of forming vessels and other objects with clay and other ceramic materials, which are fired at high temperatures to give them a hard and durable form. Major types include earthenware, stoneware and por ...
,
glass Glass is a non-crystalline, often transparent, amorphous solid that has widespread practical, technological, and decorative use in, for example, window panes, tableware, and optics. Glass is most often formed by rapid cooling (quenching) of ...
,
metal A metal (from Greek μέταλλον ''métallon'', "mine, quarry, metal") is a material that, when freshly prepared, polished, or fractured, shows a lustrous appearance, and conducts electricity and heat relatively well. Metals are typicall ...
s,
textile Textile is an umbrella term that includes various fiber-based materials, including fibers, yarns, filaments, threads, different fabric types, etc. At first, the word "textiles" only referred to woven fabrics. However, weaving is not the ...
s,
wood Wood is a porous and fibrous structural tissue found in the stems and roots of trees and other woody plants. It is an organic materiala natural composite of cellulose fibers that are strong in tension and embedded in a matrix of lignin th ...
, printed paper, and
sculpture Sculpture is the branch of the visual arts that operates in three dimensions. Sculpture is the three-dimensional art work which is physically presented in the dimensions of height, width and depth. It is one of the plastic arts. Durable sc ...
"appearing on everything from christening presents to
gravestone A headstone, tombstone, or gravestone is a stele or marker, usually stone, that is placed over a grave. It is traditional for burials in the Christian, Jewish, and Muslim religions, among others. In most cases, it has the deceased's name, da ...
s and memorials." The fashion for growing ferns indoors led to the development of the
Wardian case The Wardian case was an early type of terrarium, a sealed protective container for plants. It found great use in the 19th century in protecting foreign plants imported to Europe from overseas, the great majority of which had previously died from ...
, a glazed cabinet that would exclude air pollutants and maintain the necessary humidity. The dried form of ferns was also used in other arts, being used as a stencil or directly inked for use in a design. The botanical work, ''
The Ferns of Great Britain and Ireland ''The Ferns of Great Britain and Ireland'' was a book published in 1855 that featured 51 plates of nature printing by Henry Bradbury. Description The text was a scientific description of all the varieties of Ferns found in the British Isles. The ...
'', is a notable example of this type of
nature printing Nature printing is a printing process, developed in the 18th century, that uses the plants, animals, rocks and other natural subjects to produce an image. The subject undergoes several stages to give a direct impression onto materials such as lead, ...
. The process, patented by the artist and publisher Henry Bradbury, impressed a specimen on to a soft lead plate. The first publication to demonstrate this was
Alois Auer Alois Auer (11 May 1813 – 10 July 1869) was an Austrian printer, inventor and botanical illustrator, most active during the 1840s and 1850s. He produced a number of works in German and other languages, including the first regarding the nature pr ...
's ''The Discovery of the Nature Printing-Process''.
Fern bar Fern bar is an American slang term for an upscale or preppy (or yuppie) bar or tavern catering to singles, usually decorated with ferns or other greenery, as well as such decor as fake Tiffany lamps. The phrase came into common regional usage in ...
s were popular in America in the 1970s and 80s.


Folklore

Ferns figure in folklore, for example in legends about mythical flowers or seeds. In
Slavic folklore Slavic folklore encompasses the folklore of the Slavic peoples from their earliest records until today. Folklorists have published a variety of works focused specifically on the topic over the years.See, for example, Kononenko 2007. See also * ...
, ferns are believed to bloom once a year, during the
Ivan Kupala Kupala Night ( be, Купалле, pl, Noc Kupały, russian: Иван-Купала, uk, Івана Купала, Купайла), also called Ivanа Kupala, is a traditional Slavic holiday that was originally celebrated on the shortest night of ...
night. Although alleged to be exceedingly difficult to find, anyone who sees a
fern flower The fern flower is a magic flower in Baltic mythology ( lt, paparčio žiedas, lv, papardes zieds), in Estonian mythology ( et, sõnajalaõis) and in Slavic mythology ( be, папараць-кветка, pl, kwiat paproci, russian: цвет ...
is thought to be guaranteed to be happy and rich for the rest of their life. Similarly,
Finnish Finnish may refer to: * Something or someone from, or related to Finland * Culture of Finland * Finnish people or Finns, the primary ethnic group in Finland * Finnish language, the national language of the Finnish people * Finnish cuisine See also ...
tradition holds that one who finds the
seed A seed is an embryonic plant enclosed in a protective outer covering, along with a food reserve. The formation of the seed is a part of the process of reproduction in seed plants, the spermatophytes, including the gymnosperm and angiospe ...
of a fern in bloom on
Midsummer Midsummer is a celebration of the season of summer usually held at a date around the summer solstice. It has pagan pre-Christian roots in Europe. The undivided Christian Church designated June 24 as the feast day of the early Christian mart ...
night will, by possession of it, be guided and be able to travel invisibly to the locations where eternally blazing
Will o' the wisp In folklore, a will-o'-the-wisp, will-o'-wisp or ''ignis fatuus'' (, plural ''ignes fatui''), is an atmospheric ghost light seen by travellers at night, especially over bogs, swamps or marshes. The phenomenon is known in English folk belief, ...
s called
aarnivalkea In folklore, a will-o'-the-wisp, will-o'-wisp or ''ignis fatuus'' (, plural ''ignes fatui''), is an atmospheric ghost light seen by travellers at night, especially over bogs, swamps or marshes. The phenomenon is known in English folk belief, ...
mark the spot of hidden
treasure Treasure (from la, thesaurus from Greek language ''thēsauros'', "treasure store") is a concentration of wealth — often originating from ancient history — that is considered lost and/or forgotten until rediscovered. Some jurisdictions leg ...
. These spots are protected by a spell that prevents anyone but the fern-seed holder from ever knowing their locations. In the US, ferns are thought to have magical properties such as a dried fern can be thrown into hot coals of a fire to exorcise evil spirits, or smoke from a burning fern is thought to drive away snakes and such creatures.


New Zealand

Ferns are the national emblem of New Zealand and feature on its passport and in the design of its national airline,
Air New Zealand Air New Zealand Limited () is the flag carrier airline of New Zealand. Based in Auckland, the airline operates scheduled passenger flights to 20 domestic and 30 international destinations in 18 countries, primarily around and within the Pacific ...
, and its rugby team, the
All Blacks The New Zealand national rugby union team, commonly known as the All Blacks ( mi, Ōpango), represents New Zealand in men's international rugby union, which is considered the country's national sport. The team won the Rugby World Cup in 1987 ...
.


Organisms confused with ferns


Misnomers

Several non-fern plants (and even animals) are called ferns and are sometimes confused with ferns. These include: * Asparagus fern—This may apply to one of several species of the
monocot Monocotyledons (), commonly referred to as monocots, (Lilianae ''sensu'' Chase & Reveal) are grass and grass-like flowering plants (angiosperms), the seeds of which typically contain only one embryonic leaf, or cotyledon. They constitute one of ...
genus ''
Asparagus Asparagus, or garden asparagus, folk name sparrow grass, scientific name ''Asparagus officinalis'', is a perennial flowering plant species in the genus ''Asparagus''. Its young shoots are used as a spring vegetable. It was once classified in ...
'', which are flowering plants. * Sweetfern—A flowering shrub of the genus '' Comptonia''. *
Air fern The air fern (''Sertularia argentea'') is a species of marine animal in the family Sertulariidae. It is also known as the sea fir and Neptune plant. These so-called "ferns" are dead and dried colonies of hydrozoans, colonies of marine hydroids ...
—A group of
animal Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motilit ...
s called
hydrozoa Hydrozoa (hydrozoans; ) are a taxonomic class of individually very small, predatory animals, some solitary and some colonial, most of which inhabit saline water. The colonies of the colonial species can be large, and in some cases the specializ ...
n that are distantly related to
jellyfish Jellyfish and sea jellies are the informal common names given to the medusa-phase of certain gelatinous members of the subphylum Medusozoa, a major part of the phylum Cnidaria. Jellyfish are mainly free-swimming marine animals with umbrella- ...
and
coral Corals are marine invertebrates within the class Anthozoa of the phylum Cnidaria. They typically form compact colonies of many identical individual polyps. Coral species include the important reef builders that inhabit tropical oceans and sec ...
s. They are harvested, dried, dyed green, and then sold as a plant that can live on air. While it may look like a fern, it is merely the skeleton of this colonial animal. * Fern bush—'' Chamaebatiaria millefolium''—a rose family shrub with fern-like leaves. * Fern tree—''
Jacaranda mimosifolia ''Jacaranda mimosifolia'' is a sub-tropical tree native to south-central South America that has been widely planted elsewhere because of its attractive and long-lasting violet-colored flowers. It is also known as the jacaranda, blue jacaranda, ...
''—an
ornamental tree Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...
of the order
Lamiales The order Lamiales (also known as the mint order) are an order in the asterid group of dicotyledonous flowering plants. It includes about 23,810 species, 1,059 genera, and is divided into about 25 families. These families include Acanthaceae, Bi ...
. * Fern leaf tree—''
Filicium decipiens ''Filicium decipiens'', called the ferntree, fern tree or fern leaf tree, is a species of '' Filicium'' found in east Africa, Madagascar, India and Sri Lanka. It is planted as an ornamental tree in the Indian subcontinent, Indonesia, Hawaii, and ...
''—an
ornamental tree Ornamental plants or garden plants are plants that are primarily grown for their beauty but also for qualities such as scent or how they shape physical space. Many flowering plants and garden varieties tend to be specially bred cultivars that i ...
of the order
Sapindales Sapindales is an order of flowering plants. Well-known members of Sapindales include citrus; maples, horse-chestnuts, lychees and rambutans; mangos and cashews; frankincense and myrrh; mahogany and neem. The APG III system of 2009 includes it ...
.


Fern-like flowering plants

Some
flowering plant Flowering plants are plants that bear flowers and fruits, and form the clade Angiospermae (), commonly called angiosperms. The term "angiosperm" is derived from the Greek words ('container, vessel') and ('seed'), and refers to those plants th ...
s such as palms and members of the carrot family have
pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and in ...
leaves that somewhat resemble fern fronds. However, these plants have fully developed seeds contained in fruits, rather than the microscopic spores of ferns.


Gallery

File:CowellFerns.JPG, Ferns in one of many natural
Coast Redwood ''Sequoia sempervirens'' ()''Sunset Western Garden Book,'' 1995:606–607 is the sole living species of the genus '' Sequoia'' in the cypress family Cupressaceae (formerly treated in Taxodiaceae). Common names include coast redwood, coastal ...
undergrowth settings
Santa Cruz, CA Santa Cruz ( Spanish for "Holy Cross") is the county seat and largest city of Santa Cruz County, in Northern California. As of the 2020 census, the city population was 62,956. Situated on the northern edge of Monterey Bay, Santa Cruz is a p ...
File:FernBedInForest.jpg, Fern bed under a forest canopy in woods near
Franklin, Virginia Franklin is the southwesternmost independent city in Hampton Roads, Commonwealth of Virginia. As of the 2020 census, the population was 8,180. The Bureau of Economic Analysis combines the city of Franklin with Southampton County for statistic ...
File:Samambaia fern.jpg, Fern growing on a wall File:Silver-fern.jpg,
Silver fern ''Alsophila dealbata'', synonym ''Cyathea dealbata'', commonly known as the silver fern or silver tree-fern, or as ponga or punga (from Māori or ),The Māori word , pronounced , has been borrowed into New Zealand English as a generic term fo ...
or ''Alsophila dealbata'', endemic to
New Zealand New Zealand ( mi, Aotearoa ) is an island country in the southwestern Pacific Ocean. It consists of two main landmasses—the North Island () and the South Island ()—and over 700 smaller islands. It is the sixth-largest island count ...
File:Adiantum lunulatum W IMG 2336.jpg, ''
Adiantum philippense ''Adiantum philippense,'' (''Goyali Lota, Kalijhant'' in Bengali language, Bengali: গয়ালী লতা, ''Hamsapadi, Kitamata, Tripadika'' in Sanskrit, ''Jarigida'' in Kannada, ''Hamsapadi'' in Hindi ), also known as walking maidenhair ...
'' File:Pyrrosia piloselloides duit-duit.jpg, ', dragon's scale, in Malaysia File:Kidney Fern New Zealand. (12185571965).jpg, ''
Hymenophyllum nephrophyllum ''Hymenophyllum nephrophyllum'', the kidney fern, is a filmy fern species native to New Zealand. It commonly grows on the forest floor of open native bush. Individual kidney-shaped fronds stand about 5–10 cm tall. In hot weather they shriv ...
'', the kidney fern File:Fern02.jpg, Tree fern, probably ''
Dicksonia antarctica ''Dicksonia antarctica'', the soft tree fern or man fern, is a species of evergreen tree fern native to eastern Australia, ranging from south-east Queensland, coastal New South Wales and Victoria to Tasmania. Anatomy and biology These ferns ...
'' File:Ferns.jpg, Tree ferns, probably ''Dicksonia antarctica'' File:Haeckel Filicinae 92.jpg, "Filicinae" from
Ernst Haeckel Ernst Heinrich Philipp August Haeckel (; 16 February 1834 – 9 August 1919) was a German zoologist, naturalist, eugenicist, philosopher, physician, professor, marine biologist and artist. He discovered, described and named thousands of new sp ...
's ''
Kunstformen der Natur (known in English as ''Art Forms in Nature'') is a book of lithographic and halftone prints by German biologist Ernst Haeckel. ...
'', 1904 File:Spiraled fern.JPG, A young, newly formed fern frond File:Tree Fern.jpg, A tree fern unrolling a new frond File:Fern.jpg, Fern leaf, probably ''
Lomaria nuda ''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 ...
'' File:Fern-leaf-oliv.jpg, Leaf of fern File:Asplenium marinum Moore38.png, Nature prints in
The Ferns of Great Britain and Ireland ''The Ferns of Great Britain and Ireland'' was a book published in 1855 that featured 51 plates of nature printing by Henry Bradbury. Description The text was a scientific description of all the varieties of Ferns found in the British Isles. The ...
used fronds to produce the plates File:Fern Spores.jpg,
Sporangia A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cy ...
of ''
Dryopteris filix-mas ''Dryopteris filix-mas'', the male fern, is a common fern of the temperate Northern Hemisphere, native to much of Europe, Asia, and North America. It favours damp shaded areas in the understory of woodlands, but also shady places on hedge-banks, ...
'' File:Tree Fern Spores.jpg, Tree fern sporangia
San Diego, CA San Diego ( , ; ) is a city on the Pacific Ocean coast of Southern California located immediately adjacent to the Mexico–United States border. With a 2020 population of 1,386,932, it is the eighth most populous city in the United States ...
File:蕨類 Fern 20220406200725 02.jpg, Sporangia on a leaflet File:Fern fiddleheads.jpg File:臺灣粗榧 - 溪頭自然教育園區 Cephalotaxus wilsoniana - Xitou Nature Education Area, Taiwan 20220316205506 21.jpg, Epiphytic fern on the branch of ''
Cephalotaxus wilsoniana ''Cephalotaxus wilsoniana'' is a species of pinophyta, coniferous tree in the yew family, Taxaceae. Its common names include Taiwan plum yew, Taiwan cow's-tail pine,British Pteridological Society The British Pteridological Society is for fern enthusiasts of the British Isles, and was founded in England in 1891. The origins and early history of the BPS at the time of "Pteridomania Pteridomania or fern fever was a Victorian craze for f ...
*
Chirosia betuleti ''Chirosia betuleti'' is a species of fly, which causes knotting gall in ferns. The gall develops in the terminal shoots of ferns, such as broad buckler fern (''Dryopteris dilatata''), male fern ('' Dryopteris filix-mas''), lady fern ('' Athyrium ...
- Fern gall *
Fern spike In paleontology, a fern spike is the occurrence of unusually high spore abundance of ferns in the fossil record, usually immediately (in a geological sense) after an extinction event. The spikes are believed to represent a large, temporary inc ...
*
Fern sports Fern sports are plants that show marked change from the normal type or parent stock as a result of mutation. The term Morphotype is also used for any of a group of different types of individuals of the same species in a population. Fern fronds in s ...
*
Paisley (design) Paisley or paisley pattern is an ornamental textile design using the ''boteh'' ( fa, بته) or ''buta'', a teardrop-shaped motif with a curved upper end. Of Persian origin, paisley designs became popular in the West in the 18th and 19th centuri ...
*
Pteridophyte A pteridophyte is a vascular plant (with xylem and phloem) that disperses spores. Because pteridophytes produce neither flowers nor seeds, they are sometimes referred to as "cryptogams", meaning that their means of reproduction is hidden. Ferns, ...
*
Silver fern flag A silver fern flag is any flag design that incorporates a silver fern, and is usually a white silver fern on a black background. The silver fern motif is associated with New Zealand, and a silver fern flag may be used as an unofficial flag of N ...


Notes


References


Bibliography


Books and theses

* * , ''see also''
Species Plantarum ' (Latin for "The Species of Plants") is a book by Carl Linnaeus, originally published in 1753, which lists every species of plant known at the time, classified into genera. It is the first work to consistently apply binomial names and was the ...
* Lord, Thomas R. (2006). ''Ferns and Fern Allies of Pennsylvania''. Indiana, PA: Pinelands Press
Ferns and Fern Allies of Pennsylvania - Thomas Reeves Lord
* Moran, Robbin C. (2004). ''A Natural History of Ferns''. Portland, OR: Timber Press. . * * *


Journal articles

* * * * * * * * * * * * * * * * * * *


Websites

* * * * * * * A classification of th






L. Watson and M.J. Dallwitz (2004 onwards). The Ferns (Filicopsida) of the British Isles.





"American Fern Society"

"British Pteridological Society"

Images of ferns of Hawaii


External links

* * {{Authority control Non-timber forest products Extant Late Devonian first appearances