Leptosporangiate fern
Encyclopedia
Leptosporangiate ferns are the largest group of living fern
s. They are often considered to be the class Pteridopsida or Polypodiopsida, although other classifications assign them a different rank. The leptosporangiate ferns are one of the four major groups of ferns, with the others being Marattiopsida
, Equisetopsida
(horsetails), and Psilotopsida
(whisk ferns
and ophioglossoid fern
s).
There are approximately 9000 species of living leptosporangiate ferns, compared with about 260 for all other ferns put together. Almost a third of leptosporangiate fern species are epiphyte
s.
These ferns are called leptosporangiate because their sporangia
arose from a single epidermal cell and not from a group of cells as in eusporangiate fern
s. The sporangia are typically covered with a scale called the indusium, which can cover the whole sorus
, but can also be strongly reduced. Many leptosporangiate ferns have an annulus around the sporangium, which ejects the spores.
, Cyatheaceae
, Polypodiaceae
, Athyriaceae
, Woodsiaceae
, Onocleaceae
, Lomariopsidaceae
and Tectariaceae
.
The classification scheme proposed by Smith et al.(alternative names in brackets):
Fern
A fern is any one of a group of about 12,000 species of plants belonging to the botanical group known as Pteridophyta. Unlike mosses, they have xylem and phloem . They have stems, leaves, and roots like other vascular plants...
s. They are often considered to be the class Pteridopsida or Polypodiopsida, although other classifications assign them a different rank. The leptosporangiate ferns are one of the four major groups of ferns, with the others being Marattiopsida
Marattiopsida
Class Marattiopsida is a group of ferns containing a single order, Marattiales, and family, Marattiaceae. Class Marattiopsida diverged from other ferns very early in their evolutionary history and are quite different from many plants familiar to people in temperate zones. Many of them have massive,...
, Equisetopsida
Equisetopsida
Equisetopsida, or Sphenopsida, is a class of plants with a fossil record going back to the Devonian. They are commonly known as horsetails...
(horsetails), and Psilotopsida
Psilotopsida
Psilotopsida is a class of fern-like plants. It should not be confused with the obsolete class Psilophytopsida. As circumscribed by Smith et al. Psilotopsida contains two families, Psilotaceae and Ophioglossaceae, placed in orders Psilotales and Ophioglossales, respectively...
(whisk ferns
Psilotaceae
Psilotaceae is a family of fern-like plants consisting of two genera, Psilotum and Tmesipteris. The two genera are very different and in the past Tmesipteris has been placed in its own family, Tmesipteridaceae, but most classifications continue to treat it in Psilotaceae...
and ophioglossoid fern
Ophioglossales
Ophioglossales are a small group of pteridophyte plants. Traditionally they are included in the division Pteridophyta, the ferns, originally as a family and later as the order Ophioglossales...
s).
There are approximately 9000 species of living leptosporangiate ferns, compared with about 260 for all other ferns put together. Almost a third of leptosporangiate fern species are epiphyte
Epiphyte
An epiphyte is a plant that grows upon another plant non-parasitically or sometimes upon some other object , derives its moisture and nutrients from the air and rain and sometimes from debris accumulating around it, and is found in the temperate zone and in the...
s.
These ferns are called leptosporangiate because their sporangia
Sporangium
A sporangium is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. All plants, fungi, and many other lineages form sporangia at some point in their life cycle...
arose from a single epidermal cell and not from a group of cells as in eusporangiate fern
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...
s. The sporangia are typically covered with a scale called the indusium, which can cover the whole sorus
Sorus
A sorus is a cluster of sporangia .In fungi and lichens, the sorus is surrounded by an external layer. In some red algae it may take the form of a depression into the thallus....
, but can also be strongly reduced. Many leptosporangiate ferns have an annulus around the sporangium, which ejects the spores.
Classification
Most extant fern families are leptosporangiates. Examples are: DryopteridaceaeDryopteridaceae
Dryopteridaceae, is a family of leptosporangiate ferns in the order Polypodiales. They are known colloquially as the wood ferns. They comprise about 1700 species and have a cosmopolitan distribution. They may be terrestrial, epipetric, hemiepiphytic, or epiphytic. Many are cultivated as...
, Cyatheaceae
Cyatheaceae
The Cyatheaceae is the scaly tree fern family and includes the world's tallest tree ferns, which reach heights up to 20 m. They are also very ancient plants, appearing in the fossil record in the late Jurassic, though the modern genera likely appeared in the Tertiary. Cyatheaceae is the largest...
, Polypodiaceae
Polypodiaceae
Polypodiaceae is a family of polypod ferns, which includes more than 60 genera divided into several tribes and containing around 1,000 species. Nearly all are epiphytes, but some are terrestrial.-Description:...
, Athyriaceae
Athyriaceae
Athyriaceae is a family of terrestrial ferns, with a cosmopolitan distribution. It has, in the past, included Cystopteris and Gymnocarpium, but those two genera are now recognized as representing a two-member clade that is a basal offshoot of the clade that includes this family, plus Woodsia, the...
, Woodsiaceae
Woodsiaceae
Woodsiaceae or Cliff Fern is a family of fern within the Aspleniales order....
, Onocleaceae
Onocleaceae
Onocleaceae is a small family of terrestrial ferns. There are four genera of onocleoids: Matteuccia, Onoclea, Onocleopsis, and Pentarhizidium, consisting of five species largely in north temperate climes....
, Lomariopsidaceae
Lomariopsidaceae
The Lomariopsidaceae is a family of ferns with a largely tropical distribution. The family is here restricted to the cladistic grouping determined by the paper cited below.*Cyclopeltis*Lomariopsis*Nephrolepis...
and Tectariaceae
Tectariaceae
Tectariaceae is a family of Leptosporangiate ferns in the order Polypodiales. It comprises 10 genera. Tectaria is much larger than the other genera....
.
The classification scheme proposed by Smith et al.(alternative names in brackets):
- Order Osmundales
- Family OsmundaceaeOsmundaceaeThe Osmundaceae is a family of four genera and 15-25 species. It is the only fern family of the order Osmundales; an order in the class Pteridopsida or in some classifications the only order in the class Osmundopsida...
- Family Osmundaceae
- Order Hymenophyllales
- Family Hymenophyllaceae (incl. Trichomanaceae)
- Order Gleicheniales
- Family GleicheniaceaeGleicheniaceaeThe forked ferns are the family Gleicheniaceae. They are sometimes – like all ferns and the related horsetails – placed in an infradivision Monilophytes of subdivision Euphyllophytina, allowing for more precise phylogenetic arrangement of the tracheophytes. More conventionally, the name...
(incl. Dicranopteridaceae, Stromatopteridaceae) - Family Dipteridaceae (incl. Cheiropleuriaceae)
- Family Matoniaceae
- Family Gleicheniaceae
- Order Schizaeales
- Family Lygodiaceae
- Family Anemiaceae (incl. Mohriaceae)
- Family SchizaeaceaeSchizaeaceaeSchizaeaceae is a family of 35 to 40 species of small ferns, chiefly tropical.Genera historically treated as belonging to this family include Anemia, Lygodium, and Mohria...
- Order Salviniales
- Family MarsileaceaeMarsileaceaeThe Marsileaceae are a small family of heterosporous aquatic and semi-aquatic ferns, though at first sight they do not physically resemble other ferns. The group is commonly known as the "pepperwort family" or as the "water-clover family" because the leaves of the genus Marsilea superficially...
(incl. Pilulariaceae) - Family SalviniaceaeSalviniaceaeSalviniaceae , is a family of ferns....
(incl. Azollaceae)
- Family Marsileaceae
- Order CyathealesCyathealesThe order Cyatheales is a taxonomic division of the fern subclass, Cyatheatae, which includes the tree ferns. No clear morphological features characterize all of the Cyatheales, but DNA sequence data indicates that the order is monophyletic. Some species in the Cyatheales have tree-like growth...
- Family Thyrsopteridaceae
- Family LoxsomataceaeLoxsomataceaeLoxsomataceae is a family of ferns in the order Cyatheales. It comprises two extant genera, Loxsoma and Loxsomopsis....
- Family CulcitaceaeCulcitaceaeCulcitaceae is a family of ferns within the order Cyatheales. An example genus within the family is Culcita.-References:* C.Michael Hogan. 2010. . Washington DC....
- Family Plagiogyriaceae
- Family Cibotiaceae
- Family CyatheaceaeCyatheaceaeThe Cyatheaceae is the scaly tree fern family and includes the world's tallest tree ferns, which reach heights up to 20 m. They are also very ancient plants, appearing in the fossil record in the late Jurassic, though the modern genera likely appeared in the Tertiary. Cyatheaceae is the largest...
(incl. Alsophilaceae, Hymenophyllopsidaceae) - Family DicksoniaceaeDicksoniaceaeThe Dicksoniaceae is a family of tropical, subtropical and warm temperate ferns. Most of the 5-6 genera in the family are terrestrial ferns or have very short trunks compared to tree ferns of the family Cyatheaceae. However, some of the larger species can reach several metres in height. A number of...
(incl. Lophosoriaceae) - Family Metaxyaceae
- Order PolypodialesPolypodialesThe order Polypodiales encompasses the major lineages of polypod ferns, which comprise more than 80% of today's fern species. They are found in many parts of the world including tropical, semitropical and temperate areas...
(the Smith 2006 paper defines this order broadly; the following list also shows some of the subgroups which are sometimes considered to be separate orders)- Family LindsaeaceaeLindsaeaceaeLindsaeaseae contains genera that were formerly considered part of Dennstaedtiaceae. Molecular data supported the separation of Lindsaeaseae into its own family. Lindsaeaseae is considered the most basal of the order Polypodiales...
(incl. Cystodiaceae, Lonchitidaceae) - Family SaccolomataceaeSaccolomataceaeSaccolomataceae has been formerly treated as a member of the Dennstaedtiaceae, however it has been classified as its own family according to Smith et al....
- Family DennstaedtiaceaeDennstaedtiaceaeDennstaedtiaceae is one of fifteen families in the order Polypodiales, the most derived families within monilophytes . It includes the world's most abundant fern, Pteridium aquilinum . Members of the order generally have large, highly divided leaves and have either small, round intramarginal sori...
(incl. Hypolepidaceae, Monachosoraceae, Pteridiaceae) - Family PteridaceaePteridalesThe Pteridales are ferns that have their sori in linear strips under the edge of the leaf tissue, usually with the edge of the lamina reflexed over.This order is considered a family under the Smith classification...
(incl. Acrostichaceae, Actiniopteridaceae, AdiantaceaeAdiantaceaeAdiantaceae is a family of ferns in the order Pteridales. This includes the family formerly known as the "Vittariaceae." Recent genetic analyses based on chloroplast genes demonstrate that the vittarioid ferns cladistically nest within the genus Adiantum, making that genus...
, Anopteraceae, Antrophyaceae, CeratopteridaceaeCeratopteridaceaeCeratopteridaceae is the family name for the clade that is now known to include the two genera Ceratopteris and Acrostichum.Although Ceratopteris was long isolated under its own family, due to adaptations for a dedicated aquatic existence, recent genetic study has determined that these two genera...
, Cheilanthaceae, CryptogrammaceaeCryptogrammaceaeCryptogrammaceae is a small family of ferns, which appears to be somewhat isolated from the rest of the Pteridales. This family forms a natural clade that is the most basal to the order. Of these, Llavea is the most basal within the clade....
, Hemionitidaceae, Negripteridaceae, Parkeriaceae, Platyzomataceae, Sinopteridaceae, Taenitidaceae, Vittariaceae) - Clade Eupolypods II in Smith 2006 (Formerly, Blechnales, Athyriales, Aspleniales, or Thelypteridales)
- Family AspleniaceaeAspleniaceaeThe Aspleniaceae is a family of ferns, included in the order Polypodiales or in some classifications as the only family in the order Aspleniales....
- Family ThelypteridaceaeThelypteridaceaeThelypteridaceae is a family of about 900 species of ferns.The ferns are terrestrial, with the exception of a few which are lithophytes . The bulk of the species are tropical, although there are a number of temperate species....
- Family WoodsiaceaeWoodsiaceaeWoodsiaceae or Cliff Fern is a family of fern within the Aspleniales order....
(incl. AthyriaceaeAthyriaceaeAthyriaceae is a family of terrestrial ferns, with a cosmopolitan distribution. It has, in the past, included Cystopteris and Gymnocarpium, but those two genera are now recognized as representing a two-member clade that is a basal offshoot of the clade that includes this family, plus Woodsia, the...
, CystopteridaceaeCystopteridaceaeBased on recent cladistic evidence, Cystopteridaceae should be construed as a separate family due to its basal position, sister to all other polypodioid ferns. This clade includes only the genera Acystopteris, Cystopteris and Gymnocarpium. Woodsia is a more advanced species.The ferns in this...
) - Family BlechnaceaeBlechnaceaeBlechnaceae is a family of nine genera and between 240-260 species of ferns, with a cosmopolitan distribution.Most are ground dwelling, some are climbers, such as Stenochlaena. A characteristic feature of many species is that the young opening fronds are usually tinged with red.Genera*Blechnum L....
(incl. Stenochlaenaceae) - Family OnocleaceaeOnocleaceaeOnocleaceae is a small family of terrestrial ferns. There are four genera of onocleoids: Matteuccia, Onoclea, Onocleopsis, and Pentarhizidium, consisting of five species largely in north temperate climes....
- Family Aspleniaceae
- Clade Eupolypods IEupolypods IEupolypods I is a clade of ferns in the order Polypodiales. It probably diverged from Eupolypods II during the mid-Cretaceous. The divergence is supported by both molecular data and an often over-looked morphological characteristic which lies in the vasculature of the petiole. Most species that...
in Smith 2006- Family DryopteridaceaeDryopteridaceaeDryopteridaceae, is a family of leptosporangiate ferns in the order Polypodiales. They are known colloquially as the wood ferns. They comprise about 1700 species and have a cosmopolitan distribution. They may be terrestrial, epipetric, hemiepiphytic, or epiphytic. Many are cultivated as...
(incl. Aspidiaceae, Bolbitidaceae, ElaphoglossaceaeElaphoglossaceaeThe Elaphoglossaceae is a family that includes a clade that has been previously distributed among other families or groups. For instance, Bolbitis was long considered to be in the Lomariopsidaceae. This current classification is based on the 2007 work by Schuettpelz &...
, HypodematiaceaeHypodematiaceaeHypodematiaceae is a family of ferns in the order Polypodiales. It consists of two, or possibly three, small genera. Hypodematium and Leucostegia are always included, and Didymochlaena might best be placed in this family as well....
, Peranemataceae) - Family LomariopsidaceaeLomariopsidaceaeThe Lomariopsidaceae is a family of ferns with a largely tropical distribution. The family is here restricted to the cladistic grouping determined by the paper cited below.*Cyclopeltis*Lomariopsis*Nephrolepis...
(incl. Nephrolepidaceae) - Family TectariaceaeTectariaceaeTectariaceae is a family of Leptosporangiate ferns in the order Polypodiales. It comprises 10 genera. Tectaria is much larger than the other genera....
- Family Oleandraceae
- Family DavalliaceaeDavalliaceaeDavalliaceae is a family of ferns in the order Polypodiales. It is sister to the largest family of ferns, Polypodiaceae, and shares some morphological characters with it....
- Family PolypodiaceaePolypodiaceaePolypodiaceae is a family of polypod ferns, which includes more than 60 genera divided into several tribes and containing around 1,000 species. Nearly all are epiphytes, but some are terrestrial.-Description:...
(incl. Drynariaceae, Grammitidaceae, Gymnogrammitidaceae, Loxogrammaceae, Platyceriaceae, Pleurisoriopsidaceae)
- Family Dryopteridaceae
- Family Lindsaeaceae