A fern (Polypodiopsida or Polypodiophyta ) is a member of a group of
vascular plants (plants with
xylem and
phloem) 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
seeds nor
flowers. 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, 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
bryophytes 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. Most ferns are
leptosporangiate ferns. 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
fronds. The group includes about 10,560 known extant species. Ferns are defined here in the broad sense, being all of the
Polypodiopsida, comprising both the leptosporangiate (
Polypodiidae) and
eusporangiate ferns, the latter group including
horsetails,
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 ferns, 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, 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, as ornamental plants, and for remediating contaminated soil. They have been the subject of research for their ability to remove some chemical pollutants from the atmosphere. Some fern species, such as
bracken (''Pteridium aquilinum'') and water fern (''
Azolla filiculoides
''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'', can
fix nitrogen and make a significant input to the nitrogen nutrition of
rice paddies. They also play certain roles in folklore.
Description
![滷蕨 20190526171829](https://upload.wikimedia.org/wikipedia/commons/1/17/%E6%BB%B7%E8%95%A8_20190526171829.jpg)
Extant ferns are herbaceous
perennials and most lack
woody growth. Their foliage may be
deciduous or
evergreen, 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
bryophytes in that, like seed plants, they are
polysporangiophytes, their sporophytes branching and producing many sporangia. Also unlike bryophytes, fern sporophytes are free-living and only briefly dependent on the maternal
gametophyte.
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). 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'' in
New Zealand).
Leaves
The
green,
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''. 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
fronds. This uncurling of the leaf is termed
circinate vernation. Leaves are divided into two types: sporophylls and tropophylls.
Sporophylls produce spores;
tropophylls do not. Fern spores are borne in
sporangia 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). The fertile leaves are much narrower than the sterile leaves, and may even have no green tissue at all (e.g.,
Blechnaceae,
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
Indeterminate may refer to:
In mathematics
* Indeterminate (variable), a symbol that is treated as a variable
* Indeterminate system, a system of simultaneous equations that has more than one solution
* Indeterminate equation, an equation that ha ...
(e.g.
Gleicheniaceae,
Lygodiaceae
''Lygodium'' (climbing fern) is a genus of about 40 species of ferns, native to tropical regions across the world, with a few temperate species in eastern Asia and eastern North America. It is the sole genus in the family Lygodiaceae in the Pter ...
). The divided forms are
pinnate, 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. They are always
fibrous and structurally are very similar to the roots of seed plants.
As in all other
vascular plants, 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 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 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: 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.
*
Rhizoids:
root-like structures (not true roots) that consist of single greatly elongated cells, that absorb water and mineral
salts over the whole structure. Rhizoids anchor the prothallus to the soil.
Taxonomy
Carl Linnaeus (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). 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 of the Plant Kingdom named
Pteridophyta or Filicophyta. Pteridophyta is no longer recognised as a valid
taxon 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), Polypodiopsida, although this name sometimes only refers to leptosporangiate ferns. Traditionally, all of the spore producing
vascular plants 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 tr ...
s, and grape ferns) and
Marattiaceae; 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
clubmosses,
spikemosses, and
quillworts in
Lycopodiophyta; the whisk ferns of
Psilotaceae; and the horsetails of
Equisetaceae. Since this grouping is
polyphyletic, 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 plants, 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. 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
horsetails and
Marattiaceae 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 Tracheophyta (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 - seed plants, ~260,000 species
** Subdivision
Lycopodiophyta (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'' (see
Equisetopsida 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 (Sphenopsida) 1 order, Equisetales ( Horsetails) ~ 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 (Filicopsida) 7 orders ( leptosporangiate ferns) ~ 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 (to the level of orders).[ This division into four major clades was then confirmed using morphology 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) encompassing all land plants. This is referred to as Equisetopsida '' sensu lato'' to distinguish it from the narrower use to refer to horsetails alone, Equisetopsida ''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
Dr Maarten Joost Maria Christenhusz (born 27 April 1976) is a Dutch botanist, natural historian and photographer.
Career
He was born in Enschede, the Netherlands, received his undergraduate and master's degrees from Utrecht University in Bi ...
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 (=Equisetopsida) - monotypic (Equisetales, Equisetaceae, '' Equisetum'') horsetails ~ 20 species)
* Ophioglossidae (=Psilotopsida) - 2 monotypic orders ~ 92 species
* Marattiidae (=Marattiopsida) - 1 monotypic order (Marattiales, Marattiaceae, 2 subfamilies) ~ 130 species
* Polypodiidae (=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, 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) 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
Mya may refer to:
Brands and product names
* Mya (program), an intelligent personal assistant created by Motorola
* Mya (TV channel), an Italian Television channel
* Midwest Young Artists, a comprehensive youth music program
Codes
* Burmese ...
. By the Triassic, the first evidence of ferns related to several modern families appeared. The great fern radiation occurred in the late Cretaceous, 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 from hornworts, a bryophyte 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 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 habitats, from remote mountain 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 plants. Some ferns are among the world's most serious weed species, including the bracken fern growing in the Scottish highlands, or the mosquito fern ('' Azolla'') 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 forests; 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 trees, 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 fungi. Many ferns grow only within specific pH ranges; for instance, the climbing fern (''Lygodium palmatum
''Lygodium palmatum'' is the only species of its genus native to North America. Unlike most species in the genus, this one, called the American climbing fern (or Hartford fern, after Hartford, Connecticut), is extremely hardy in temperate zones ...
'') 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, and ...
''), with an overlapping range, is found only on limestone.
The spores are rich in lipids, protein and calories, so some vertebrates eat these. The European woodmouse (''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 that ...
'', 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 plants differing from lycophytes 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. They differ from seed plants ( gymnosperms 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 flowers and seeds. 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 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 chromosomes, 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 (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.
# The gametophyte produces gametes (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 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), ''Matteuccia struthiopteris'' ( ostrich fern), 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) 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 and the South Pacific
The Pacific Ocean is the largest and deepest of Earth's five oceanic divisions. It extends from the Arctic Ocean in the north to the Southern Ocean (or, depending on definition, to Antarctica) in the south, and is bounded by the continen ...
. Fern tubers were used for food 30,000 years ago in Europe. Fern tubers were used by the Guanches to make gofio 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 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 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 infestations.
Many ferns are grown in horticulture as landscape plants, for cut foliage and as houseplants, 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 weeds 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'', the sensitive fern, also known as the bead fern, is a coarse-textured, medium to large-sized deciduous perennial fern. The name comes from its sensitivity to frost, the fronds dying quickly when first touched by it. It is ...
(''Onoclea sensibilis'') and Giant water fern ('' Salvinia molesta''), one of the world's worst aquatic weeds. The important fossil fuel coal 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, and formerly in the US Pharmacopeia; also, this fern accidentally sprouting in a bottle resulted in Nathaniel Bagshaw Ward's 1829 invention of the terrarium or Wardian case
* '' Rumohra adiantiformis'' (floral fern), extensively used in the florist trade
* '' Microsorum pteropus'' (Java fern), one of the most popular freshwater aquarium plants.
* '' Osmunda regalis'' (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'' 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 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 ferns, 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 lycophytes.
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 craze of fern collecting 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, glass, metals, textiles, wood, printed paper, and sculpture "appearing on everything from christening presents to gravestones and memorials." The fashion for growing ferns indoors led to the development of the Wardian case, 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's ''The Discovery of the Nature Printing-Process''.
Fern bars 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, 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: цвето ...
is thought to be guaranteed to be happy and rich for the rest of their life. Similarly, Finnish tradition holds that one who finds the seed of a fern in bloom on Midsummer night will, by possession of it, be guided and be able to travel invisibly to the locations where eternally blazing Will o' the wisps 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. 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, and its rugby team, the All Blacks.
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 genus '' Asparagus'', which are flowering plants.
* Sweetfern—A flowering shrub of the genus '' Comptonia''.
* Air fern—A group of animals called hydrozoan that are distantly related to jellyfish and corals. 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
''Chamaebatiaria'' is a monotypic genus of aromatic shrub in the rose family containing the single species ''Chamaebatiaria millefolium'', which is known by the common names fern bush and desert sweet. Its genus name comes from its physical resem ...
''—a rose family shrub with fern-like leaves.
* Fern tree—'' Jacaranda mimosifolia''—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.
* 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.
Fern-like flowering plants
Some flowering plants such as palms and members of the carrot family
Apiaceae or Umbelliferae is a family of mostly aromatic flowering plants named after the type genus '' Apium'' and commonly known as the celery, carrot or parsley family, or simply as umbellifers. It is the 16th-largest family of flowering plan ...
have pinnate 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 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
File:Samambaia fern.jpg, Fern growing on a wall
File:Silver-fern.jpg, Silver fern or ''Alsophila dealbata'', endemic to New Zealand
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''
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 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
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''
See also
* British Pteridological Society
* Chirosia betuleti - 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 incre ...
* 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)
* 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. .
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* 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
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{{Authority control
Non-timber forest products
Extant Late Devonian first appearances