''Asplenium trichomanes'', the maidenhair spleenwort, is a small

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 except th ...

in the spleenwort

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 nomencla ...

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 ...

''. It is a widespread and common species, occurring almost worldwide in a variety of rocky

habitat In ecology, the term habitat summarises the array of resources, physical and biotic factors that are present in an area, such as to support the survival and reproduction of a particular species. A species habitat can be seen as the physical ...

s. It is a variable fern with several

subspecies In biological classification, subspecies is a rank below species, used for populations that live in different areas and vary in size, shape, or other physical characteristics (morphology), but that can successfully interbreed. Not all species ...

. The

specific epithet In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

''trichomanes'' refers to a Greek word for fern.

Description

''Asplenium trichomanes'' grows 10 to 30 cm tall forming tufts arising from a short, scaly

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 ho ...

. The scales are dark. The evergreen

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 are long and narrow, gradually tapering towards the tip. They are simply divided into small, yellow-green to dark-green, roundish pinnae. The stipe and

rachis In biology, a rachis (from the grc, ῥάχις [], "backbone, spine") is a main axis or "shaft". In zoology and microbiology In vertebrates, ''rachis'' can refer to the series of articulated vertebrae, which encase the spinal cord. In this c ...

of the frond are dark all along their length. The fronds can reach 40 cm in length but are more commonly 8–20 cm. The

indusia A sorus (pl. sori) is a cluster of sporangia (structures producing and containing spores) in ferns and fungi. A coenosorus (plural coenosori) is a compound sorus composed of multiple, fused sori. Etymology This New Latin word is from Ancient G ...

are linear to oval, straight, and attached to the upper-side of the fertile vein. There are (2) 4 to 8 sori per pinna and each are 1 to 3.5 mm long. Diploid (2n) chromosome count is 72.

Distribution and habitat

It is widespread in

temperate In geography, the temperate climates of Earth occur in the middle latitudes (23.5° to 66.5° N/S of Equator), which span between the tropics and the polar regions of Earth. These zones generally have wider temperature ranges throughout t ...

and

subarctic The subarctic zone is a region in the Northern Hemisphere immediately south of the true Arctic, north of humid continental regions and covering much of Alaska, Canada, Iceland, the north of Scandinavia, Siberia, and the Cairngorms. Genera ...

areas and also occurs in mountainous regions in the

tropics The tropics are the regions of Earth surrounding the Equator. They are defined in latitude by the Tropic of Cancer in the Northern Hemisphere at N and the Tropic of Capricorn in the Southern Hemisphere at S. The tropics are also referred to ...

. Its range includes most of Europe and much of Asia south to

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula in ...

Iran Iran, officially the Islamic Republic of Iran, and also called Persia, is a country located in Western Asia. It is bordered by Iraq and Turkey to the west, by Azerbaijan and Armenia to the northwest, by the Caspian Sea and Turkme ...

and the

Himalayas The Himalayas, or Himalaya (; ; ), is a mountain range in Asia, separating the plains of the Indian subcontinent from the Tibetan Plateau. The range has some of the planet's highest peaks, including the very highest, Mount Everest. Over 100 ...

with a population in

Yemen Yemen (; ar, ٱلْيَمَن, al-Yaman), officially the Republic of Yemen,, ) is a country in Western Asia. It is situated on the southern end of the Arabian Peninsula, and borders Saudi Arabia to the north and Oman to the northeast and sha ...

. It occurs in northern, southern and parts of eastern Africa and also in eastern

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guinea. In ...

, south-east Australia,

Tasmania ) , nickname = , image_map = Tasmania in Australia.svg , map_caption = Location of Tasmania in AustraliaCoordinates: , subdivision_type = Country , subdi ...

, New Zealand and

Hawaii Hawaii ( ; haw, Hawaii or ) is a U.S. state, state in the Western United States, Western United States, located in the Pacific Ocean about from the U.S. mainland. It is the only U.S. state outside North America, the only state that is ...

. It is found in

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 C ...

and

Central America Central America ( es, América Central or ) is a subregion of the Americas. Its boundaries are defined as bordering the United States to the north, Colombia to the south, the Caribbean Sea to the east, and the Pacific Ocean to the west. C ...

and Cuba, and the northern and western regions of South America such as

Chile Chile, officially the Republic of Chile, is a country in the western part of South America. It is the southernmost country in the world, and the closest to Antarctica, occupying a long and narrow strip of land between the Andes to the east a ...

. Even though its range is wide spread, it is often rare, and populations are widely spread out from each other based on the available of suitable habitat. It grows in rocky habitats such as cliffs,

scree Scree is a collection of broken rock fragments at the base of a cliff or other steep rocky mass that has accumulated through periodic rockfall. Landforms associated with these materials are often called talus deposits. Talus deposits typically h ...

slopes, walls and mine waste, the type of rock used as a substrate depending on the subspecies. It grows from sea-level up to 3000 metres in North America while in the British Isles it reaches 870 metres. In the US state of

Minnesota Minnesota () is a state in the upper midwestern region of the United States. It is the 12th largest U.S. state in area and the 22nd most populous, with over 5.75 million residents. Minnesota is home to western prairies, now given over to ...

''A. trichomanes'' is listed as a threatened species. It occurs on ledges and in crevices on moist, east-facing cliffs and occasionally on talus with similar conditions. The Minnesota populations are ''Asplenium trichomanes'' subsp. ''trichomanes''.

Cultivation

''Asplenium trichomanes'' is valued in cultivation for its hardiness (down to ), its evergreen foliage and its ability to colonise crevices in stone walls. It prefers a fully or partially shaded aspect. It 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 (N ...

’s

Award of Garden Merit The Award of Garden Merit (AGM) is a long-established annual award for plants by the British Royal Horticultural Society (RHS). It is based on assessment of the plants' performance under UK growing conditions. History The Award of Garden Merit ...

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 ...

was the first to describe maidenhair spleenwort with the

binomial Binomial may refer to: In mathematics *Binomial (polynomial), a polynomial with two terms *Binomial coefficient, numbers appearing in the expansions of powers of binomials *Binomial QMF, a perfect-reconstruction orthogonal wavelet decomposition * ...

''Asplenium trichomanes'' in his ''

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 ...

'' of 1753. ''Asplenium trichomanes'' has diploid, tetraploid and hexaploid

cytotype A karyotype is the general appearance of the complete set of metaphase chromosomes in the cells of a species or in an individual organism, mainly including their sizes, numbers, and shapes. Karyotyping is the process by which a karyotype is disce ...

s, which it has been argued should be recognised as distinct species. A triploid cytotype (a sterile hybrid between the diploid and tetraploid cytotype) is also known. Within these cytotypes several subspecies are recognised, including *''Asplenium trichomanes'' subsp. ''trichomanes'' prefers

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 ...

ic rocks such as

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicates) ...

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90% of a ...

and

granite Granite () is a coarse-grained (phaneritic) intrusive igneous rock composed mostly of quartz, alkali feldspar, and plagioclase. It forms from magma with a high content of silica and alkali metal oxides that slowly cools and solidifies underg ...

. In Europe and North America it is most often found in mountainous areas and is commonest in the north. It is a delicate plant with a slender stipe and rachis and relatively few pinnae. Diploid. *''Asplenium trichomanes'' subsp. ''quadrivalens'' prefers

calcareous Calcareous () is an adjective meaning "mostly or partly composed of calcium carbonate", in other words, containing lime or being chalky. The term is used in a wide variety of scientific disciplines. In zoology ''Calcareous'' is used as an adje ...

rocks such as

limestone Limestone ( calcium carbonate ) is a type of carbonate sedimentary rock which is the main source of the material lime. It is composed mostly of the minerals calcite and aragonite, which are different crystal forms of . Limestone forms when ...

and

dolomite Dolomite may refer to: *Dolomite (mineral), a carbonate mineral *Dolomite (rock), also known as dolostone, a sedimentary carbonate rock *Dolomite, Alabama, United States, an unincorporated community *Dolomite, California, United States, an unincor ...

and often grows on the mortar in walls. It is commoner than ''A. t.'' subsp. ''trichomanes'' in much of Europe but is less widespread in North America, although it is present in southern North America where ssp. ''trichomanes'' is absent. Compared to the nominate subspecies it is stouter and has more pinnae which are more square in shape and have less of a stalk. The fronds tend to grow close to the rock while those of ''A. t.'' subsp. ''trichomanes'' tend to arch away. Tetraploid. *''Asplenium trichomanes'' subsp. ''pachyrachis'' (syn. ''Asplenium csikii'') is mainly found on limestone rocks and walls. It is small and delicate, grows close to the rock and has a rigid, fragile stipe and rachis. Tetraploid. * ''Asplenium trichomanes'' subsp. ''coriaceifolium'' (syn. ''Asplenium azomanes''):

Majorca Mallorca, or Majorca, is the largest island in the Balearic Islands, which are part of Spain and located in the Mediterranean. The capital of the island, Palma, is also the capital of the autonomous community of the Balearic Islands. The Ba ...

, Spain, Morocco. Tetraploid. Asplenium trichomanes2

*''Asplenium trichomanes'' subsp. ''hastatum''. Tetraploid. *''Asplenium trichomanes'' subsp. ''inexpectans''. Diploid. *''Asplenium trichomanes'' subsp. ''maderense''. Madeira, Azores. Hexaploid. Hexaploids also occur in Australia and New Zealand. *''Asplenium trichomanes'' nothosubsp. ''staufferi''. Tetraploid (''pachyrachis'' × ''quadrivalens''). *''Asplenium trichomanes'' nothosubsp. ''barraraense''. Tetraploid (''coraceifolium'' × ''quadrivalens''). *''Asplenium trichomanes'' nothosubsp. ''lovisianum''. Tetraploid (''hastatum'' × ''quadrivalens''). *''Asplenium trichomanes'' nothosubsp. ''moravicum''. Tetraploid (''hastatum'' × ''pachyrachis''). *''Asplenium trichomanes'' nothosubsp. ''melzeranum''. Triploid (''hastatum'' × ''inexpectans''). *''Asplenium trichomanes'' nothosubsp. ''melzeri''. Triploid (''quadrivalens'' × ''inexpectans''). *''Asplenium trichomanes'' nothosubsp. ''tadei-reichsteinii''. Triploid (''pachyrachis'' × ''inexpectans''). *''Asplenium trichomanes'' nothosubsp. ''lusaticum''. Triploid (''trichomanes'' × ''quadrivalens''). *''Asplenium trichomanes'' nothosubsp. ''malacitense''. Triploid (''coraceifolium'' × ''inexpectans'').

References

*Flora of North America
''Asplenium trichomanes''
Accessed 13 August 2008. *Hutchinson, G. (1996) ''Welsh Ferns'', National Museums and Galleries of Wales. *Page C. N. (1982) ''The Ferns of Britain and Ireland'', Cambridge University Press. *Preston, C. D. & Pearman, D. A. (2002) ''New Atlas of the British and Irish Flora'', Oxford University Press. * Stace, Clive A. (1997) ''New Flora of the British Isles'', Cambridge University Press. *Tutin, T. G. ''et al.'' (1964) ''

Flora Europaea The ''Flora Europaea'' is a 5-volume encyclopedia of plants, published between 1964 and 1993 by Cambridge University Press. The aim was to describe all the national Floras of Europe in a single, authoritative publication to help readers identify ...

'', Volume 1. Cambridge University Press.

External links

BSBI Maps: Distribution in Britain and IrelandPlants for a Future databaseFlora of Pennsylvania
{{Taxonbar, from=Q902211 trichomanes Ferns of the Americas Ferns of Asia Ferns of Europe Ferns of Australasia Ferns of the United States Alpine flora Tropical flora Flora of Central America Flora of South America Flora of Australasia Flora of Asia Flora of Australia Plants described in 1753 Taxa named by Carl Linnaeus