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Schiedea Verticillata
''Schiedea verticillata'', known as the Devils Slide schiedea or Nihoa carnation, is an endangered species of plant in the family Caryophyllaceae, endemic to the island of Nihoa in the Northwestern Hawaiian Islands, where it was discovered in 1923 by the ''Tanager'' Expedition. It has been listed as endangered since 1996. It has stems long, erect or sometimes trailing, and fleshy mint-colored leaves as long as 15 cm. The flowers are petal-less, have ten stamens and 4-5 styles. The plant estivates, dying back to the fleshy perennial roots during the dry season. Less than 400 individual plants survive in two of Nihoa's rocky valleys, but the population has remained stable. How this plant is pollinated is not known. Even though there are very few individuals surviving, the carnation can avoid inbreeding, a problem that threatens fellow Nihoan plant ''Amaranthus brownii'', because this carnation has the highest genetic diversity of its genus. Notes References * External li ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Forest B
A forest is an area of land dominated by trees. Hundreds of definitions of forest are used throughout the world, incorporating factors such as tree density, tree height, land use, legal standing, and ecological function. The United Nations' Food and Agriculture Organization (FAO) defines a forest as, "Land spanning more than 0.5 hectares with trees higher than 5 meters and a canopy cover of more than 10 percent, or trees able to reach these thresholds ''in situ''. It does not include land that is predominantly under agricultural or urban use." Using this definition, '' Global Forest Resources Assessment 2020'' (FRA 2020) found that forests covered , or approximately 31 percent of the world's land area in 2020. Forests are the predominant terrestrial ecosystem of Earth, and are found around the globe. More than half of the world's forests are found in only five countries (Brazil, Canada, China, Russia, and the United States). The largest share of forests (45 percent) are in th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Perennial Plant
A perennial plant or simply perennial is a plant that lives more than two years. The term ('' per-'' + '' -ennial'', "through the years") is often used to differentiate a plant from shorter-lived annuals and biennials. The term is also widely used to distinguish plants with little or no woody growth (secondary growth in girth) from trees and shrubs, which are also technically perennials. Perennialsespecially small flowering plantsthat grow and bloom over the spring and summer, die back every autumn and winter, and then return in the spring from their rootstock or other overwintering structure, are known as herbaceous perennials. However, depending on the rigours of local climate (temperature, moisture, organic content in the soil, microorganisms), a plant that is a perennial in its native habitat, or in a milder garden, may be treated by a gardener as an annual and planted out every year, from seed, from cuttings, or from divisions. Tomato vines, for example, live several y ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endemic Flora Of Nihoa
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] |
Schiedea
''Schiedea'' is a genus of flowering plants in the family Caryophyllaceae. It contains 34 species and is endemic to Hawaii. A 35th species was spotted in 2017 by Tom DeMent while surveying a forest near Laupāhoehoe on Hawai‘i Island. It has yet to be named. Selected species *''Schiedea adamantis'' H.St.John - Diamond Head schiedea (Oahu, Hawaii) *''Schiedea amplexicaulis'' H.Mann *'' Schiedea apokremnos'' H.St.John *''Schiedea attenuata'' W.L.Wagner, Weller & Sakai *''Schiedea diffusa'' A.Gray *''Schiedea globos'' H.Mann *'' Schiedea haleakalensis'' Degener & Sherff in Sherff *''Schiedea hawaiiensis'' Hillebrand *'' Schiedea helleri'' Sherff *'' Schiedea hookeri'' A.Gray *''Schiedea implexa'' (Hillebrand) SherffAdvanced *''Schiedea jacobii'' W.L.Wagner, Weller & Madeiros in W.L.Wagner et al. *'' Schiedea kaalae'' Wawra - Maolioli (Oʻahu, Hawaii) *'' Schiedea kauaiensis'' H.St.John *'' Schiedea kealiae'' Caum & Hosaka *''Schiedea laui'' W.L.Wagner & Weller *''Schiedea ligustr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bishop Museum
The Bernice Pauahi Bishop Museum, designated the Hawaii State Museum of Natural and Cultural History, is a museum of history and science in the historic Kalihi district of Honolulu on the Hawaiian island of Oʻahu. Founded in 1889, it is the largest museum in Hawaiʻi and has the world's largest collection of Polynesian cultural artifacts and natural history specimens. Besides the comprehensive exhibits of Hawaiian cultural material, the museum's total holding of natural history specimens exceeds 24 million, of which the entomological collection alone represents more than 13.5 million specimens (making it the third-largest insect collection in the United States). The '' Index Herbariorum'' code assigned to Herbarium Pacificum of this museum is BISH and this abbreviation is used when citing housed herbarium specimens. The museum complex is home to the Richard T. Mamiya Science Adventure Center. History Establishment Charles Reed Bishop (1822–1915), a businessman and philant ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Genetic Diversity
Genetic diversity is the total number of genetic characteristics in the genetic makeup of a species, it ranges widely from the number of species to differences within species and can be attributed to the span of survival for a species. It is distinguished from ''genetic variability'', which describes the tendency of genetic characteristics to vary. Genetic diversity serves as a way for populations to adapt to changing environments. With more variation, it is more likely that some individuals in a population will possess variations of alleles that are suited for the environment. Those individuals are more likely to survive to produce offspring bearing that allele. The population will continue for more generations because of the success of these individuals. The academic field of population genetics includes several hypotheses and theories regarding genetic diversity. The neutral theory of evolution proposes that diversity is the result of the accumulation of neutral substitutions ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Amaranthus Brownii
''Amaranthus brownii'' was an annual herb in the family Amaranthaceae. The plant was found only on the small island of Nihoa in the Northwestern Hawaiian Islands, growing on rocky outcrops at altitudes of . It was one of nine species of ''Amaranthus'' in the Hawaiian Islands, as well as the only endemic Hawaiian species of the genus. It is now considered extinct. ''A. brownii'' was first discovered during the Tanager Expedition in 1923 by botanist Edward Leonard Caum. It differed from other Hawaiian species of ''Amaranthus'' with its spineless leaf axils, linear leaves, and indehiscent fruits. It was one of 26 vascular plants on Nihoa, 17 of which are indigenous, six alien, and three endemic only to Nihoa; these latter three included ''A. brownii'', the Nihoa fan palm or ''loulu'', and the Nihoa carnation. ''A. brownii'' was considered the rarest plant on Nihoa and was not directly observed on the island after 1983. Past expeditions collected plant samples and seeds, but n ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pollination
Pollination is the transfer of pollen from an anther of a plant to the stigma of a plant, later enabling fertilisation and the production of seeds, most often by an animal or by wind. Pollinating agents can be animals such as insects, birds, and bats; water; wind; and even plants themselves, when self-pollination occurs within a closed flower. Pollination often occurs within a species. When pollination occurs between species, it can produce hybrid offspring in nature and in plant breeding work. In angiosperms, after the pollen grain (gametophyte) has landed on the stigma, it germinates and develops a pollen tube which grows down the style until it reaches an ovary. Its two gametes travel down the tube to where the gametophyte(s) containing the female gametes are held within the carpel. After entering an ovum cell through the micropyle, one male nucleus fuses with the polar bodies to produce the endosperm tissues, while the other fuses with the ovule to produce the embr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Dry Season
The dry season is a yearly period of low rainfall, especially in the tropics. The weather in the tropics is dominated by the tropical rain belt, which moves from the northern to the southern tropics and back over the course of the year. The temperate counterpart to the tropical dry season is summer or winter. Rain belt The tropical rain belt lies in the southern hemisphere roughly from October to March; during that time the northern tropics have a dry season with sparser precipitation, and days are typically sunny throughout. From April to September, the rain belt lies in the northern hemisphere, and the southern tropics have their dry season. Under the Köppen climate classification, for tropical climates, a dry season month is defined as a month when average precipitation is below . The rain belt reaches roughly as far north as the Tropic of Cancer and as far south as the Tropic of Capricorn. Near these latitudes, there is one wet season and one dry season annually. At the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Estivation
Aestivation ( la, aestas (summer); also spelled estivation in American English) is a state of animal dormancy, similar to hibernation, although taking place in the summer rather than the winter. Aestivation is characterized by inactivity and a lowered metabolic rate, that is entered in response to high temperatures and arid conditions. It takes place during times of heat and dryness, the hot dry season, which are often the summer months. Invertebrate and vertebrate animals are known to enter this state to avoid damage from high temperatures and the risk of desiccation. Both terrestrial and aquatic animals undergo aestivation. Fossil records suggest that aestivation may have evolved several hundred million years ago. Physiology Organisms that aestivate appear to be in a fairly "light" state of dormancy, as their physiological state can be rapidly reversed, and the organism can quickly return to a normal state. A study done on '' Otala lactea'', a snail native to parts of Eu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Endangered Species
An endangered species is a species that is very likely to become extinct in the near future, either worldwide or in a particular political jurisdiction. Endangered species may be at risk due to factors such as habitat loss, poaching and invasive species. The International Union for Conservation of Nature (IUCN) Red List lists the global conservation status of many species, and various other agencies assess the status of species within particular areas. Many nations have laws that protect conservation-reliant species which, for example, forbid hunting, restrict land development, or create protected areas. Some endangered species are the target of extensive conservation efforts such as captive breeding and habitat restoration. Human activity is a significant cause in causing some species to become endangered. Conservation status The conservation status of a species indicates the likelihood that it will become extinct. Multiple factors are considered when assessing the ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Stamen
The stamen (plural ''stamina'' or ''stamens'') is the pollen-producing reproductive organ of a flower. Collectively the stamens form the androecium., p. 10 Morphology and terminology A stamen typically consists of a stalk called the filament and an anther which contains ''sporangium, microsporangia''. Most commonly anthers are two-lobed and are attached to the filament either at the base or in the middle area of the anther. The sterile tissue between the lobes is called the connective, an extension of the filament containing conducting strands. It can be seen as an extension on the dorsal side of the anther. A pollen grain develops from a microspore in the microsporangium and contains the male gametophyte. The stamens in a flower are collectively called the androecium. The androecium can consist of as few as one-half stamen (i.e. a single locule) as in ''Canna (plant), Canna'' species or as many as 3,482 stamens which have been counted in the saguaro (''Carnegiea gigantea'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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