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Asplenium Haughtonii
''Asplenium haughtonii'', also known as the Barn fern, is a species of fern in the family Aspleniaceae. It is native to Saint Helena. Taxonomy A global phylogeny of ''Asplenium'' published in 2020 divided the genus into eleven clades, which were given informal names pending further taxonomic study. ''A. haughtonii'' belongs to the "''A. cordatum'' subclade" of the "''Schaffneria'' clade". The ''Schaffneria'' clade has a worldwide distribution, and members vary widely in form and habitat. There is no clear morphological feature that unites the ''A. cordatum'' subclade. The sister species of ''A. haughtonii'' is '' A. phillipsianum'' from Socotra, and the two together are sister to the African '' A. cordatum''. These three are scaly ferns of dry habitats; the other two species in the subclade are sister to them, and are walking ferns, with long undivided leaves and proliferating leaf tips. Etymology The English name Barn fern is derived from a basal ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 the lycopods, and differ from mosses 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 is the dominant phase. Ferns have complex leaves called megaphylls, that are more complex than the microphylls of clubmosses. Most ferns are leptosporangiate ferns. They produce coiled fiddleheads 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, marattioid ferns, and ophioglossoid fe ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Aspleniaceae
The Aspleniaceae (spleenworts) are a family of ferns, included in the order Polypodiales. The composition and classification of the family have been subject to considerable changes. In particular, there is a narrow circumscription, Aspleniaceae s.s. (adopted here), in which the family contains only two genera, and a very broad one, Aspleniaceae s.l., in which the family includes 10 other families kept separate in the narrow circumscription, with the Aspleniaceae s.s. being reduced to the subfamily Asplenioideae. The family has a worldwide distribution, with many species in both temperate and tropical areas. Elongated unpaired sori are an important characteristic of most members of the family. Description Members of the family grow from rhizomes, that are either creeping or somewhat erect, and are usually but not always unbranched, and have scales that usually have a lattice-like (clathrate) structure. In some species, for example ''Asplenium nidus'', the rhizomes form a kind ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Saint Helena
Saint Helena () is a British overseas territory located in the South Atlantic Ocean. It is a remote volcanic tropical island west of the coast of south-western Africa, and east of Rio de Janeiro in South America. It is one of three constituent parts of the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha. Saint Helena measures about and has a population of 4,439 per the 2021 census. It was named after Helena, mother of Constantine I. It is one of the most remote islands in the world and was uninhabited when discovered by the Portuguese enroute to the Indian subcontinent in 1502. For about four centuries the island was an important stopover for ships from Europe to Asia and back, while sailing around the African continent, until the opening of the Suez canal. St Helena is the United Kingdom's second-oldest overseas territory after Bermuda. Saint Helena is known for being the site of Napoleon's second exile, following his final defeat in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asplenium Phillipsianum
''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. The type species for the genus is ''Asplenium marinum''. The most common vernacular name is spleenworts, applied to the more "typical" species. '' A. nidus'' and several similar species are called bird's-nest ferns, the ''Camptosorus'' group is known as walking ferns, and distinct names are applied to some other particularly well-known species. Taxonomy and genetics Many groups of species have been separated from ''Asplenium'' as segregate genera. These include ''Camptosorus'', ''Ceterach'', ''Phyllitis'', and ''Tarachia'', but these species can form hybrids with other ''Asplenium'' species and because of this are usually included in a more broadly defined ''Asplenium''. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Socotra
Socotra or Soqotra (; ar, سُقُطْرَىٰ ; so, Suqadara) is an island of the Republic of Yemen in the Indian Ocean, under the ''de facto'' control of the UAE-backed Southern Transitional Council, a secessionist participant in Yemen’s ongoing civil war. Lying between the Guardafui Channel and the Arabian Sea and near major shipping routes, Socotra is the largest of the four islands in the Socotra archipelago. Since 2013, the archipelago has constituted the Socotra Governorate. The island of Socotra represents around 95% of the landmass of the Socotra archipelago. It lies south of the Arabian Peninsula, but is considered to be part of Africa. The island is isolated and home to a high number of endemic species. Up to a third of its plant life is endemic. It has been described as "the most alien-looking place on Earth." The island measures in length and in width. In 2008 Socotra was recognised as a UNESCO World Heritage Site. In 2018, the United Arab Emirates ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asplenium Cordatum
''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. The type species for the genus is ''Asplenium marinum''. The most common vernacular name is spleenworts, applied to the more "typical" species. '' A. nidus'' and several similar species are called bird's-nest ferns, the ''Camptosorus'' group is known as walking ferns, and distinct names are applied to some other particularly well-known species. Taxonomy and genetics Many groups of species have been separated from ''Asplenium'' as segregate genera. These include ''Camptosorus'', ''Ceterach'', ''Phyllitis'', and ''Tarachia'', but these species can form hybrids with other ''Asplenium'' species and because of this are usually included in a more broadly defined ''Asplenium''. Some ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Walking Fern
Walking fern may refer to two species of fern in the genus ''Asplenium'' which are occasionally placed in a separate genus ''Camptosorus''. The name "walking fern" derives from the fact that new plantlets grow wherever the arching leaves of the parent touch the ground, creating a walking effect. Both have evergreen, undivided, slightly leathery leaves which are triangular and taper to a thin point. On the bottom of the leaves, sori, or spore-bearing structures, cluster along the veins. These hardy plants can be found in shady spots of limestone ledges and limy forest places. *'' Asplenium rhizophyllum'' (syn: ''Camptosorus rhizophyllum''), native to North America *'' Asplenium ruprechtii'' (syn: ''Camptosorus sibiricus''), native to East Asia It may also refer to: *'' Adiantum caudatum'', a species of maidenhair fern ''Adiantum'' (), the maidenhair fern, is a genus of about 250 species of ferns in the subfamily Vittarioideae of the family Pteridaceae, though some resear ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Drylands
Drylands are defined by a scarcity of water. Drylands are zones where precipitation is balanced by evaporation from surfaces and by transpiration by plants (evapotranspiration). The United Nations Environment Program defines drylands as tropical and temperate areas with an aridity index of less than 0.65."Millennium Ecosystem Assessment, 2005. Drylands Systems". Chapter 22 in: ''Ecosystems and Human Wellbeing: Current State and Trends'', Volume 1. Island Press. One can classify drylands into four sub-types: * Dry sub-humid lands * Demi-arid lands * Arid lands * Hyper-arid lands Some authorities regard hyper-arid lands as deserts (United Nations Convention to Combat Desertification - UNCCD) although a number of the world's deserts include both hyper-arid and arid climate zones. The UNCCD excludes hyper-arid zones from its definition of drylands. Drylands cover 41.3% of the earth's land surface, including 15% of Latin America, 66% of Africa, 40% of Asia, and 24% of Europe. Ther ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
St Helena Airport
Saint Helena Airport is an international airport on Saint Helena, a remote island in the south Atlantic Ocean, in the British Overseas Territory of Saint Helena, Ascension, and Tristan da Cunha. The construction of the runway was finished in 2015 and the airport opened in 2016. The inaugural scheduled flight was delayed but general aviation, charter, and medical evacuation flights were able to serve the airport from May 2016. The airport began scheduled commercial services on 14 October 2017, when the South African carrier Airlink inaugurated a weekly service from O. R. Tambo International Airport in Johannesburg, South Africa, via Walvis Bay Airport, Namibia, using an Embraer E190-100IGW, about one and a half years after the originally expected inauguration date, and with a smaller-sized aircraft, because of wind shear problems affecting the airport. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Saint Helena
The flora of Saint Helena, an isolated island in the South Atlantic Ocean, is exceptional in its high level of endemism and the severe threats facing the survival of the flora. In phytogeography, it is in the phytochorion St. Helena and Ascension Region of the African Subkingdom, in the Paleotropical Kingdom. Endemic and introduced flora The endemic plants of Saint Helena include many notable Cabbage Tree or, "insular arborescent Asteraceae", members of the daisy family which have evolved a shrubby or tree-like habit on islands. Other notable endemics include the closely related St Helena redwood ('' Trochetiopsis erythroxylon'') and St Helena dwarf ebony ('' Trochetiopsis ebenus''). These are unrelated to the redwood trees of California or to the ebony trees of commerce, being instead in the Mallow family (Malvaceae). Vegetation Today there are three major vegetation zones: the tree-fern thicket of the highest parts of the central ridge; the pastures of middle elevations and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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