''Asplenium scolopendrium'', commonly known as the hart's-tongue fern,
is an
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, whic ...
fern
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 exce ...
in the
genus
Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial nom ...
''
Asplenium
''Asplenium'' is a genus of about 700 species of ferns, often treated as the only genus in the family Aspleniaceae, though other authors consider '' Hymenasplenium'' separate, based on molecular phylogenetic analysis of DNA sequences, a different ...
'' native to the Northern Hemisphere.
Description
The most striking and unusual feature of the fern is its simple, undivided
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 leaves' supposed resemblance to the tongue of a
hart
Hart often refers to:
* Hart (deer)
Hart may also refer to:
Organizations
* Hart Racing Engines, a former Formula One engine manufacturer
* Hart Skis, US ski manufacturer
* Hart Stores, a Canadian chain of department stores
* Hart's Reptile Wo ...
(an archaic term for a male
red deer
The red deer (''Cervus elaphus'') is one of the largest deer species. A male red deer is called a stag or hart, and a female is called a hind. The red deer inhabits most of Europe, the Caucasus Mountains region, Anatolia, Iran, and parts of we ...
) gave rise to the common name "hart's-tongue fern".
Taxonomy
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 ...
first gave the hart's-tongue fern the
binomial ''Asplenium scolopendrium'' in his ''
Species Plantarum'' of 1753. The Latin
specific epithet ''scolopendrium'' is derived from the Greek ''skolopendra'', meaning a centipede or millipede; this is due to the
sori pattern being reminiscent of a
myriapod
Myriapods () are the members of subphylum Myriapoda, containing arthropods such as millipedes and centipedes. The group contains about 13,000 species, all of them terrestrial.
The fossil record of myriapods reaches back into the late Silurian, ...
's legs.
A global phylogeny of ''Asplenium'' published in 2020 divided the genus into eleven clades, which were given informal names pending further taxonomic study. ''A. scolopendrium'' belongs to the "''Phyllitis'' subclade" of the "''Phyllitis'' clade". Members of the ''Phyllitis'' clade have undivided or pinnatifid leaf blades with a thick, leathery texture, persistent scales on their stalk, and often possess
anastomosing
An anastomosis (, plural anastomoses) is a connection or opening between two things (especially cavities or passages) that are normally diverging or branching, such as between blood vessels, leaf veins, or streams. Such a connection may be normal ...
veins. Members of the ''Phyllitis'' subclade have undivided leaves with freely branching veins and single or paired sori. They are widely distributed through the Northern Hemisphere. Its closest relative within the subclade is ''
A. komarovii'', with which it forms a clade (the former segregate genus ''Phyllitis''), sister to ''
A. sagittatum''.
Three variations or subspecies are currently known:
*''A. scolopendrium'' var. ''scolopendrium'', the most common variation, is native to
Eurasia
Eurasia (, ) is the largest continental area on Earth, comprising all of Europe and Asia. Primarily in the Northern and Eastern Hemispheres, it spans from the British Isles and the Iberian Peninsula in the west to the Japanese archipelago ...
and
North Africa
North Africa, or Northern Africa is a region encompassing the northern portion of the African continent. There is no singularly accepted scope for the region, and it is sometimes defined as stretching from the Atlantic shores of Mauritania in ...
;
*''A. scolopendrium'' var. ''americanum'', a threatened variation, is native to the
United States
The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 states, a federal district, five major unincorporated territori ...
and
Canada
Canada is a country in North America. Its ten provinces and three territories extend from the Atlantic Ocean to the Pacific Ocean and northward into the Arctic Ocean, covering over , making it the world's second-largest country by tot ...
;
*''A. scolopendrium'' var. ''lindenii'', the least-studied variation, is native to
Mexico
Mexico (Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guatema ...
and
Hispaniola.
Morphological differences between the variations are minor, but the North American variations (i.e. ''americanum'' and ''lindenii'') are
tetraploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei (eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains ...
, while the
Old World variation (i.e. ''scolopendrium'') is
diploid.
Some taxonomists group ''lindenii'' with ''americanum'', leaving just two variations.
Distribution
''Asplenium scolopendrium'' is a common species in the Old World:
*The variation ''scolopendrium'' has been found throughout
Europe
Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a subcontinent of Eurasia and it is located entirel ...
(including the
Caucasus
The Caucasus () or Caucasia (), is a region between the Black Sea and the Caspian Sea, mainly comprising Armenia, Azerbaijan, Georgia (country), Georgia, and parts of Southern Russia. The Caucasus Mountains, including the Greater Caucasus range ...
and the
British Isles
The British Isles are a group of islands in the North Atlantic Ocean off the north-western coast of continental Europe, consisting of the islands of Great Britain, Ireland, the Isle of Man, the Inner and Outer Hebrides, the Northern Isles, ...
), the
Middle East
The Middle East ( ar, الشرق الأوسط, ISO 233: ) is a geopolitical region commonly encompassing Arabia (including the Arabian Peninsula and Bahrain), Asia Minor (Asian part of Turkey except Hatay Province), East Thrace (Europ ...
, and North Africa (in
Morocco
Morocco (),, ) officially the Kingdom of Morocco, is the westernmost country in the Maghreb region of North Africa. It overlooks the Mediterranean Sea to the north and the Atlantic Ocean to the west, and has land borders with Algeria t ...
,
Algeria
)
, image_map = Algeria (centered orthographic projection).svg
, map_caption =
, image_map2 =
, capital = Algiers
, coordinates =
, largest_city = capital
, relig ...
,
Tunisia
)
, image_map = Tunisia location (orthographic projection).svg
, map_caption = Location of Tunisia in northern Africa
, image_map2 =
, capital = Tunis
, largest_city = capital
, ...
and
Libya
Libya (; ar, ليبيا, Lībiyā), officially the State of Libya ( ar, دولة ليبيا, Dawlat Lībiyā), is a country in the Maghreb region in North Africa. It is bordered by the Mediterranean Sea to the north, Egypt to the east, Suda ...
, as well as the
Canary Islands); it has also been introduced to the
Falkland Islands
The Falkland Islands (; es, Islas Malvinas, link=no ) is an archipelago in the South Atlantic Ocean on the Patagonian Shelf. The principal islands are about east of South America's southern Patagonian coast and about from Cape Dubouze ...
of
South America
South America is a continent entirely in the Western Hemisphere and mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere at the northern tip of the continent. It can also be described as the sout ...
. Specimens of this variation found in North America (such as in
New Brunswick
New Brunswick (french: Nouveau-Brunswick, , locally ) is one of the thirteen provinces and territories of Canada. It is one of the three Maritime provinces and one of the four Atlantic provinces. It is the only province with both English and ...
and
Ontario
Ontario ( ; ) is one of the thirteen provinces and territories of Canada.Ontario is located in the geographic eastern half of Canada, but it has historically and politically been considered to be part of Central Canada. Located in Central C ...
in Canada, and
Maryland
Maryland ( ) is a state in the Mid-Atlantic region of the United States. It shares borders with Virginia, West Virginia, and the District of Columbia to its south and west; Pennsylvania to its north; and Delaware and the Atlantic Ocean to ...
in the United States) are considered naturalized descendants of cultivated plants.
In
North America, it occurs in rare, widely scattered populations located in different locales:
*The variation ''lindenii'' grows in the Mexican states of
Chiapas,
Coahuila,
Nuevo León, and
Oaxaca
Oaxaca ( , also , , from nci, Huāxyacac ), officially the Free and Sovereign State of Oaxaca ( es, Estado Libre y Soberano de Oaxaca), is one of the 32 states that compose the political divisions of Mexico, Federative Entities of Mexico. It is ...
, as well as the
Caribbean island of Hispaniola.
*The variation ''americanum'' mostly grows along the
Onondaga Limestone and
Niagara Escarpment geological formations in
Central New York
Central New York is the central region of New York State, including the following counties and cities:
With a population of about 773,606 (2009) and an area of , the region includes the Syracuse metropolitan area.
Definitions
The New York ...
(present in 2 counties),
southern Ontario
Southern Ontario is a primary region of the province of Ontario, Canada, the other primary region being Northern Ontario. It is the most densely populated and southernmost region in Canada. The exact northern boundary of Southern Ontario is disp ...
(present in 7 counties), and the eastern
Upper Peninsula
The Upper Peninsula of Michigan – also known as Upper Michigan or colloquially the U.P. – is the northern and more elevated of the two major landmasses that make up the U.S. state of Michigan; it is separated from the Lower Peninsula by ...
in
Michigan
Michigan () is a U.S. state, state in the Great Lakes region, Great Lakes region of the Upper Midwest, upper Midwestern United States. With a population of nearly 10.12 million and an area of nearly , Michigan is the List of U.S. states and ...
(present in 2 counties). Exceptions are
disjunct population
In biology, a taxon with a disjunct distribution is one that has two or more groups that are related but considerably separated from each other geographically. The causes are varied and might demonstrate either the expansion or contraction of a s ...
s that exist in
Alabama
(We dare defend our rights)
, anthem = "Alabama"
, image_map = Alabama in United States.svg
, seat = Montgomery
, LargestCity = Huntsville
, LargestCounty = Baldwin County
, LargestMetro = Greater Birmingham
, area_total_km2 = 135,765 ...
(in
Fern Cave National Wildlife Refuge, a wildlife refuge centered around an off-limits cave in
Jackson County, Alabama
Jackson County is the northeasternmost county in the U.S. state of Alabama. As of the 2020 census, the population was 52,579. The county seat is Scottsboro. The county was named for Andrew Jackson, general in the United States Army and afterw ...
, where it has declined heavily due to illegal plant collecting, and an undisclosed pit in
Morgan County that is also off-limits and protected), and
Tennessee
Tennessee ( , ), officially the State of Tennessee, is a landlocked state in the Southeastern region of the United States. Tennessee is the 36th-largest by area and the 15th-most populous of the 50 states. It is bordered by Kentucky to th ...
(in just a single county); these southern populations are at dire risk of
extirpation
Local extinction, also known as extirpation, refers to a species (or other taxon) of plant or animal that ceases to exist in a chosen geographic area of study, though it still exists elsewhere. Local extinctions are contrasted with global extinct ...
.
An
introduced population descended from New York plants is found in
New Jersey
New Jersey is a state in the Mid-Atlantic and Northeastern regions of the United States. It is bordered on the north and east by the state of New York; on the east, southeast, and south by the Atlantic Ocean; on the west by the Delaware ...
; it is a remnant of a 1936 effort to practice
ex-situ conservation
Svalbard GLOBAL SEED BANK, an ''ex situ'' conservation.
''Ex situ'' conservation literally means, "off-site conservation". It is the process of protecting an endangered species, variety or breed, of plant or animal outside its natural habitat; ...
of populations in New York.
*In 2020, a new population of hart's-tongue ferns was discovered inside of a cave with basaltic lava flows in
El Malpais National Monument
El Malpais National Monument is a National Monument located in western New Mexico, in the Southwestern United States. The name El Malpais is from the Spanish term '' Malpaís'', meaning ''badlands'', due to the extremely barren and dramatic volca ...
,
Cibola County, New Mexico
Cibola County is a county in the U.S. state of New Mexico. As of the 2010 census, the population was 27,213. Its county seat is Grants. It is New Mexico's youngest county, and the third youngest county in the United States, created on June 19, ...
; this represents the first confirmed population of the species in North America west of the Mississippi. Genetic analyses and surveys are currently being performed to determine the population's variation and overall health.
Habitat
The plants grow on neutral, calcium-rich, and/or lime-rich substrates under deciduous hardwood canopies (usually
sugar maple
''Acer saccharum'', the sugar maple, is a species of flowering plant in the soapberry and lychee family Sapindaceae. It is native to the hardwood forests of eastern Canada and eastern United States. Sugar maple is best known for being the prim ...
s in eastern North America), including moist soil and damp crevices in old walls; they are found most commonly in shaded areas. Plants in full sun are usually stunted and yellowish in colour, while those in full shade are dark green and healthy. The disjunct populations of the North American variation in the southeastern US are found exclusively in sinkhole pits or limestone caves.
[ These populations may be relics of cooler ]Pleistocene
The Pleistocene ( , often referred to as the ''Ice age'') is the geological epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was finally confirmed in ...
climates.
Conservation
United States
In the United States, ''A. scolopendrium'' var. ''americanum'' was declared endangered by the U.S. Fish and Wildlife Service
The United States Fish and Wildlife Service (USFWS or FWS) is an agency within the United States Department of the Interior dedicated to the management of fish, wildlife, and natural habitats. The mission of the agency is "working with othe ...
in 1989. The reasons for its rarity are currently being researched, with reintroduction programs in New York and elsewhere also in development.
Canada
Ontario, Canada has the highest population numbers of ''A. scolopendrium'' var. ''americanum'' of any region in the variation's distribution, with around 80% of all subpopulations and around 94% of all individuals. The fern was reported at more than 100 sites across the province, with around 75 still believed to be existing. Despite this, ''A. scolopendrium'' var. ''americanum'' was listed as a species of Special Concern under the Committee on the Status of Species at Risk in Ontario in May 2017, due to its extremely specific habitat requirements, relatively small distribution, and some subpopulations consisting of too little individuals.
Europe
In spite of being much more common in Europe than in North America (and therefore present in more protected areas), ''A. scolopendrium'' is still declining in certain areas of the continent. The fern was listed as "Vulnerable" in the National Red Lists for Albania
Albania ( ; sq, Shqipëri or ), or , also or . officially the Republic of Albania ( sq, Republika e Shqipërisë), is a country in Southeastern Europe. It is located on the Adriatic and Ionian Seas within the Mediterranean Sea and shares ...
in 2014 and Norway
Norway, officially the Kingdom of Norway, is a Nordic country in Northern Europe, the mainland territory of which comprises the western and northernmost portion of the Scandinavian Peninsula. The remote Arctic island of Jan Mayen and the ...
in 2010 (under Criterion D1); considered "critically threatened and rare" in the Czech Republic
The Czech Republic, or simply Czechia, is a landlocked country in Central Europe. Historically known as Bohemia, it is bordered by Austria to the south, Germany to the west, Poland to the northeast, and Slovakia to the southeast. The ...
's 2012 plant Red List; and "Endangered" in Sweden's 2010 Red List. However, it was not considered threatened in Germany
Germany,, officially the Federal Republic of Germany, is a country in Central Europe. It is the second most populous country in Europe after Russia, and the most populous member state of the European Union. Germany is situated betwe ...
's 1996 Red List of Threatened Plants. ''A. scolopendrium'' is protected by law in the Netherlands
)
, anthem = ( en, "William of Nassau")
, image_map =
, map_caption =
, subdivision_type = Sovereign state
, subdivision_name = Kingdom of the Netherlands
, established_title = Before independence
, established_date = Spanish Netherl ...
since 1998.
Uses
Cultivation
''Asplenium scolopendrium'' is often grown as an ornamental plant
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 ...
, with several cultivar
A cultivar is a type of cultivated plant that people have selected for desired traits and when propagated retain those traits. Methods used to propagate cultivars include: division, root and stem cuttings, offsets, grafting, tissue culture ...
s selected with varying frond form, including with frilled frond margins, forked fronds and cristate forms. The species has gained the Royal Horticultural Society
The Royal Horticultural Society (RHS), founded in 1804 as the Horticultural Society of London, is the UK's leading gardening charity.
The RHS promotes horticulture through its five gardens at Wisley (Surrey), Hyde Hall (Essex), Harlow Carr (Nor ...
's Award of Garden Merit, as has the cultivar
'Angustatum'.
The American variation is reputed to be difficult to cultivate (making conservation efforts for it even more troublesome); due to this, most, if not all, cultivated individuals are derived from the Old World variation.
Herbal medicine
This fern was used in the 1800s as a medicinal plant
Medicinal plants, also called medicinal herbs, have been discovered and used in traditional medicine practices since prehistoric times. Plants synthesize hundreds of chemical compounds for various functions, including defense and protection ag ...
in folk medicine as a spleen
The spleen is an organ found in almost all vertebrates. Similar in structure to a large lymph node, it acts primarily as a blood filter. The word spleen comes . tonic (hence an archaic name for the genus, "spleenworts") and for other uses.
Gallery
Phyllitis scolopendrium habitat.jpg, Habitat
Phyllitis scolopendrium3.jpg,
Spiers harts tongue fern.JPG,
Asplenium scolopendrium americanum.jpg,
References
*
*
Further reading
* Hyde, H. A., Wade, A. E., & Harrison, S. G. (1978). ''Welsh Ferns''. National Museum of Wales. .
* A popular article on hart's tongue fern that includes several references and a discussion of cultivation possibilities for the European and American varieties. The article strongly discourages collection and or cultivation of the North American variety.
External links
Commentary and video on Hart's Tongue ferns at Lynn Glen, Dalry, Scotland
{{Authority control
scolopendrium
Garden plants of North America
Medicinal plants of North America
Plants described in 1753
Ferns of Europe
Ferns of Asia
Ferns of the Americas
Taxa named by Carl Linnaeus