Asplenium trichomanes
Encyclopedia
Asplenium trichomanes is a small fern
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...

 in the spleenwort genus
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...

 Asplenium
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 chromosome count, and structural differences in the rhizomes...

. It is a widespread and common species, occurring almost worldwide in a variety of rocky habitat
Habitat
* Habitat , a place where a species lives and grows*Human habitat, a place where humans live, work or play** Space habitat, a space station intended as a permanent settlement...

s. It is a variable fern with several subspecies
Subspecies
Subspecies in biological classification, is either a taxonomic rank subordinate to species, ora taxonomic unit in that rank . A subspecies cannot be recognized in isolation: a species will either be recognized as having no subspecies at all or two or more, never just one...

.

Description

It grows in tufts from a short rhizome
Rhizome
In botany and dendrology, a rhizome is a characteristically horizontal stem of a plant that is usually found underground, often sending out roots and shoots from its nodes...

. The frond
Frond
The term frond refers to 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...

s are long and narrow, gradually tapering towards the tip. They are simply divided into small, yellow-green to dark-green pinna
Pinna
In animal anatomy, the pinna is the visible part of the ear that resides outside of the head ....

e. The stipe
Stipe (botany)
In botany, a stipe is a stalk that supports some other structure. The precise meaning is different depending on which taxonomic group is being described....

 and rachis
Rachis
Rachis is a biological term for a main axis or "shaft".-In zoology:In vertebrates a rachis can refer to the series of articulated vertebrae, which encase the spinal cord. In this case the rachis usually form the supporting axis of the body and is then called the spine or vertebral column...

 of the frond are dark all along their length. The fronds can reach 40 cm in length but are more commonly 8-20 cm. They bear long, narrow sori
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....

 which contain the spore
Spore
In biology, a spore is a reproductive structure that is adapted for dispersal and surviving for extended periods of time in unfavorable conditions. Spores form part of the life cycles of many bacteria, plants, algae, fungi and some protozoa. According to scientist Dr...

s.

Subspecies

Asplenium trichomanes has diploid, tetraploid and hexaploid cytotypes, 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
    Acid
    An acid is a substance which reacts with a base. Commonly, acids can be identified as tasting sour, reacting with metals such as calcium, and bases like sodium carbonate. Aqueous acids have a pH of less than 7, where an acid of lower pH is typically stronger, and turn blue litmus paper red...

    ic rocks such as sandstone
    Sandstone
    Sandstone is a sedimentary rock composed mainly of sand-sized minerals or rock grains.Most sandstone is composed of quartz and/or feldspar because these are the most common minerals in the Earth's crust. Like sand, sandstone may be any colour, but the most common colours are tan, brown, yellow,...

    , basalt
    Basalt
    Basalt is a common extrusive volcanic rock. It is usually grey to black and fine-grained due to rapid cooling of lava at the surface of a planet. It may be porphyritic containing larger crystals in a fine matrix, or vesicular, or frothy scoria. Unweathered basalt is black or grey...

     and granite
    Granite
    Granite is a common and widely occurring type of intrusive, felsic, igneous rock. Granite usually has a medium- to coarse-grained texture. Occasionally some individual crystals are larger than the groundmass, in which case the texture is known as porphyritic. A granitic rock with a porphyritic...

    . 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
    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:...

     rocks such as limestone
    Limestone
    Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate . Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera....

     and dolerite and often grows on the mortar
    Mortar (masonry)
    Mortar is a workable paste used to bind construction blocks together and fill the gaps between them. The blocks may be stone, brick, cinder blocks, etc. Mortar becomes hard when it sets, resulting in a rigid aggregate structure. Modern mortars are typically made from a mixture of sand, a binder...

     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
    Asplenium trichomanes subsp. coriaceifolium
    Asplenium trichomanes subsp. coriaceifolium is an allotetraploid hybrid fern of the Aspleniaceae family. It was found for the first time in the Soller Valley in the Serra de Tramuntana of the island of Mallorca, Spain, and described by both Spanish and German botanists at the same time...

     (syn. Asplenium azomanes): Majorca, Spain, Morocco. Tetraploid.
  • 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).

Distribution and habitat

It is widespread in temperate
Temperate
In geography, temperate or tepid latitudes of the globe lie between the tropics and the polar circles. The changes in these regions between summer and winter are generally relatively moderate, rather than extreme hot or cold...

 and subarctic
Subarctic
The Subarctic is a region in the Northern Hemisphere immediately south of the true Arctic and covering much of Alaska, Canada, the north of Scandinavia, Siberia, and northern Mongolia...

 areas and also occurs in mountainous regions in the tropics
Tropics
The tropics is a region of the Earth surrounding the Equator. It is limited in latitude by the Tropic of Cancer in the northern hemisphere at approximately  N and the Tropic of Capricorn in the southern hemisphere at  S; these latitudes correspond to the axial tilt of the Earth...

. Its range includes most of Europe and much of Asia south to Turkey
Turkey
Turkey , known officially as the Republic of Turkey , is a Eurasian country located in Western Asia and in East Thrace in Southeastern Europe...

, Iran
Iran
Iran , officially the Islamic Republic of Iran , is a country in Southern and Western Asia. The name "Iran" has been in use natively since the Sassanian era and came into use internationally in 1935, before which the country was known to the Western world as Persia...

 and the Himalayas
Himalayas
The Himalaya Range or Himalaya Mountains Sanskrit: Devanagari: हिमालय, literally "abode of snow"), usually called the Himalayas or Himalaya for short, is a mountain range in Asia, separating the Indian subcontinent from the Tibetan Plateau...

 with a population in Yemen
Yemen
The Republic of Yemen , commonly known as Yemen , is a country located in the Middle East, occupying the southwestern to southern end of the Arabian Peninsula. It is bordered by Saudi Arabia to the north, the Red Sea to the west, and Oman to the east....

. It occurs in northern, southern and parts of eastern Africa and also in eastern Indonesia
Indonesia
Indonesia , officially the Republic of Indonesia , is a country in Southeast Asia and Oceania. Indonesia is an archipelago comprising approximately 13,000 islands. It has 33 provinces with over 238 million people, and is the world's fourth most populous country. Indonesia is a republic, with an...

, south-east Australia, Tasmania
Tasmania
Tasmania is an Australian island and state. It is south of the continent, separated by Bass Strait. The state includes the island of Tasmania—the 26th largest island in the world—and the surrounding islands. The state has a population of 507,626 , of whom almost half reside in the greater Hobart...

, New Zealand and Hawaii
Hawaii
Hawaii is the newest of the 50 U.S. states , and is the only U.S. state made up entirely of islands. It is the northernmost island group in Polynesia, occupying most of an archipelago in the central Pacific Ocean, southwest of the continental United States, southeast of Japan, and northeast of...

. It is found in North America
North America
North America is a continent wholly within the Northern Hemisphere and almost wholly within the Western Hemisphere. It is also considered a northern subcontinent of the Americas...

 and Central America
Central America
Central America is the central geographic region of the Americas. It is the southernmost, isthmian portion of the North American continent, which connects with South America on the southeast. When considered part of the unified continental model, it is considered a subcontinent...

 and Cuba
Cuba
The Republic of Cuba is an island nation in the Caribbean. The nation of Cuba consists of the main island of Cuba, the Isla de la Juventud, and several archipelagos. Havana is the largest city in Cuba and the country's capital. Santiago de Cuba is the second largest city...

, and the northern and western regions of South America
South America
South America is a continent situated in the Western Hemisphere, mostly in the Southern Hemisphere, with a relatively small portion in the Northern Hemisphere. The continent is also considered a subcontinent of the Americas. It is bordered on the west by the Pacific Ocean and on the north and east...

 such as Chile
Chile
Chile ,officially the Republic of Chile , is a country in South America occupying a long, narrow coastal strip between the Andes mountains to the east and the Pacific Ocean to the west. It borders Peru to the north, Bolivia to the northeast, Argentina to the east, and the Drake Passage in the far...

.

It grows in rocky habitats such as cliffs, scree
Scree
Scree, also called talus, is a term given to an accumulation of broken rock fragments at the base of crags, mountain cliffs, or valley shoulders. Landforms associated with these materials are sometimes called scree slopes or talus piles...

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.

External links

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