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Marattia Purpurascens
''Ptisana purpurascens'' is a large fern belonging to the botanical family Marattiaceae. It has a globular rhizome with stipule-like fleshy outgrowths. The leaves are dark green, twice pinnate and up to 1 metre long. Every pinnule has up to six pairs of leaflets. The petioles are dark-purplish, hence the name 'purpurascens' meaning 'becoming purple'. The sporangia are fused in all ''Ptisana'' into a bivalvate synangium. Conservation plans have been proposed for ''Ptisana purpurascens'', an endemic of the distant Ascension Island in the South Atlantic, where a single population remains on Green Mountain. While the mature plants are still present in large numbers, long-term threats to its survival exist in the form of competition with alien invasive species like introduced plants such as ''Buddleja madagascariensis ''Buddleja madagascariensis'', the smokebush or Madagascan butterfly bush, is a species of flowering plant in the figwort family Scrophulariaceae. It is a substant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
The IUCN Red List Of Threatened Species
The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biological species. It uses a set of precise criteria to evaluate the extinction risk of thousands of species and subspecies. These criteria are relevant to all species and all regions of the world. With its strong scientific base, the IUCN Red List is recognized as the most authoritative guide to the status of biological diversity. A series of Regional Red Lists are produced by countries or organizations, which assess the risk of extinction to species within a political management unit. The aim of the IUCN Red List is to convey the urgency of conservation issues to the public and policy makers, as well as help the international community to reduce species extinction. According to IUCN the formally stated goals of the Red List are to provide sc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Synangium
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores. Fungi In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. Although sexual reproduction in fungi varies between phyla, for some fungi the sporangium plays an indirect role in sexual reproducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Near Threatened Plants
NEAR or Near may refer to: People * Thomas J. Near, US evolutionary ichthyologist * Near, a developer who created the higan emulator Science, mathematics, technology, biology, and medicine * National Emergency Alarm Repeater (NEAR), a former alarm device to warn civilians of a foreign nuclear attack on the United States * National Emergency Airway Registry (NEAR), a patient registry for intubations in the United States * Nicking enzyme amplification reaction (NEAR), a method of DNA amplification * NEAR Shoemaker, a spacecraft that studied the near-Earth asteroid Eros * Nearness or proximity space *"Near", a city browser by NearGlobal Television, film, music, and books * Near (Death Note), ''Nate River'', a character Other uses * Near v. Minnesota, a U.S. press freedom Supreme Court decision * New England Auto Racers Hall of Fame The New England Auto Racers Hall of Fame is a hall of fame for racing-related people in the New England region of the United States. NEAR was ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Ascension Island
Flora is all the plant life present in a particular region or time, generally the naturally occurring (indigenous) native plants. Sometimes bacteria and fungi are also referred to as flora, as in the terms ''gut flora'' or ''skin flora''. Etymology The word "flora" comes from the Latin name of Flora, the goddess of plants, flowers, and fertility in Roman mythology. The technical term "flora" is then derived from a metonymy of this goddess at the end of the sixteenth century. It was first used in poetry to denote the natural vegetation of an area, but soon also assumed the meaning of a work cataloguing such vegetation. Moreover, "Flora" was used to refer to the flowers of an artificial garden in the seventeenth century. The distinction between vegetation (the general appearance of a community) and flora (the taxonomic composition of a community) was first made by Jules Thurmann (1849). Prior to this, the two terms were used indiscriminately.Thurmann, J. (1849). ''Essai de Phyt ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Marattiidae
Marattiaceae is the only family of extant (living) ferns in the order Marattiales. In the Pteridophyte Phylogeny Group classification of 2016 (PPG I), Marattiales is the only order in the subclass Marattiidae. The family has six genera and about 110 species. Many are different in appearance from other ferns, having large fronds and fleshy rootstocks. Description The Marattiaceae 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, fleshy rootstocks and the largest known fronds of any fern. The Marattiaceae is one of two groups of ferns traditionally known as eusporangiate ferns, meaning that the sporangium is formed from a group of cells as opposed to a leptosporangium in which there is a single initial cell. The large fronds characteristic of the group are most readily found in the genus ''Angiopteris'', native to Australasia, Madagascar and Oceania. These fro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Buddleja Madagascariensis
''Buddleja madagascariensis'', the smokebush or Madagascan butterfly bush, is a species of flowering plant in the figwort family Scrophulariaceae. It is a substantial evergreen shrub with fragrant yellow flowers through autumn and winter. Description ''Buddleja madagascariensis'' makes a sparse, lax shrub < in height. The dark green leaves are opposite, narrowly , < 12 cm long, with petioles < 2 cm long, the surface bearing impressed |
Green Mountain
Green Mountain is a common name for "The Peak", the highest point on Ascension Island, which has gained some fame for claims that it is one of very few large-scale artificial forests. History and vegetation Many early 19th-century accounts, including Charles Darwin's (July 1836), described the volcanic island as barren with very few plants, some of them endemic to the island, not to be found anywhere else. Scientists estimate the island's native vascular plants to be between 25 and 30 species, 10 of them endemic to Ascension. This impoverished flora is a consequence of the age of the island (only 1 million years old) and isolation (over from any major landmass). Then, in 1843, the British plant collector Joseph Dalton Hooker visited the island with Sir James Clark Ross's Antarctica expedition. Hooker proposed a plan to plant the island with vegetation to attempt to increase rainfall and make life more bearable for the garrison that was stationed there. Crucially he saw the ap ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ascension Island
Ascension Island is an isolated volcanic island, 7°56′ south of the Equator in the South Atlantic Ocean. It is about from the coast of Africa and from the coast of South America. It is governed as part of the British Overseas Territory of Saint Helena, Ascension and Tristan da Cunha, of which the main island, Saint Helena, is around to the southeast. The territory also includes the sparsely populated Tristan da Cunha archipelago, to the south, about halfway to the Antarctic Circle. Named after the day of its recorded discovery, Ascension of Jesus, Ascension Island was an important safe haven as a coaling station to mariners and a refueling stop for commercial airliners back in the days of international air travel by flying boats. Ascension Island was garrisoned by the British Admiralty from 22 October 1815 to 1922. During World War II, it was an important naval and air station, especially providing antisubmarine warfare bases in the Battle of the Atlantic.Victory at ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemism
Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsewhere. For example, the Cape sugarbird is found exclusively in southwestern South Africa and is therefore said to be ''endemic'' to that particular part of the world. An endemic species can be also be referred to as an ''endemism'' or in scientific literature as an ''endemite''. For example '' Cytisus aeolicus'' is an endemite of the Italian flora. '' Adzharia renschi'' was once believed to be an endemite of the Caucasus, but it was later discovered to be a non-indigenous species from South America belonging to a different genus. The extreme opposite of an endemic species is one with a cosmopolitan distribution, having a global or widespread range. A rare alternative term for a species that is endemic is "precinctive", which applies to ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporangia
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores. Fungi In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. Although sexual reproduction in fungi varies between phyla, for some fungi the sporangium plays an indirect role in sexual reproducti ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
IUCN
The International Union for Conservation of Nature (IUCN; officially International Union for Conservation of Nature and Natural Resources) is an international organization working in the field of nature conservation and sustainable use of natural resources. It is involved in data gathering and analysis, research, field projects, advocacy, and education. IUCN's mission is to "influence, encourage and assist societies throughout the world to conserve nature and to ensure that any use of natural resources is equitable and ecologically sustainable". Over the past decades, IUCN has widened its focus beyond conservation ecology and now incorporates issues related to sustainable development in its projects. IUCN does not itself aim to mobilize the public in support of nature conservation. It tries to influence the actions of governments, business and other stakeholders by providing information and advice and through building partnerships. The organization is best known to the wider ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petiole (botany)
In botany, the petiole () is the stalk that attaches the leaf blade to the stem, and is able to twist the leaf to face the sun. This gives a characteristic foliage arrangement to the plant. Outgrowths appearing on each side of the petiole in some species are called stipules. Leaves with a petiole are said to be petiolate, while leaves lacking a petiole are called sessile or apetiolate. Description The petiole is a stalk that attaches a leaf to the plant stem. In petiolate leaves, the leaf stalk may be long, as in the leaves of celery and rhubarb, or short. When completely absent, the blade attaches directly to the stem and is said to be sessile. Subpetiolate leaves have an extremely short petiole, and may appear sessile. The broomrape family Orobanchaceae is an example of a family in which the leaves are always sessile. In some other plant groups, such as the speedwell genus '' Veronica'', petiolate and sessile leaves may occur in different species. In the grasses (Poaceae), ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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