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Tetradesmus Smithii
''Tetradesmus'' is a genus of green algae in the family Scenedesmaceae. Species of ''Tetradesmus'' are found in a variety of habitats, including fresh water and biological soil crusts in deserts. Taxonomy The genus ''Tetradesmus'' was described by Gilbert Morgan Smith, containing the single species '' Tetradesmus wisconsinensis''. It was not universally accepted; Robert Hippolyte Chodat synonymized the genus into ''Scenedesmus'', while George Stephen West accepted the genus as separate from ''Scenedesmus''. In the 2000s, molecular data revealed found that ''Scenedesmus'' was polyphyletic. ''Scenedesmus'' was subsequently split up into several genera, corresponding to the former subgenera In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the ge ... ''Scenedesmus'', ''Desmodesmus'', and ''Ac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetradesmus Dimorphus
''Tetradesmus dimorphus'' is a freshwater unicellular green algae in the class Chlorophyceae. The name means "having two forms". ''Tetradesmus dimorphus'' consists of colonies of two, four or eight cells, which are arranged linearly or in a zigzag fashion, in one or two rows. Cells are (5–)6–25(–27) μm long and 2–9.4(–14) μm wide, broadly spindle-shaped, tapered to points at both ends. The inner cells are straight, while marginal cells have ends that are slightly curved outwards. Synonyms Basionym * ''Achnanthes dimorpha'' Turpin Homotypic synonyms * ''Achnanthes dimorpha'' Turpin, 1828 * ''Scenedesmus obliquus'' var. ''dimorphus'' (Turpin) Hansgirg * ''Scenedesmus acutus'' var. ''dimorphus'' (Turpin) Rabenhorst * ''Scenedesmus dimorphus'' (Turpin) Kützing Heterotypic synonyms * ''Scenedesmus antennatus'' Brébisson in Ralfs * ''Scenedesmus costulatus'' Chodat * ''Scenedesmus acutus'' var. ''obliquus'' Rabenhorst See also * Algaculture Algaculture is a form of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gilbert Morgan Smith
Gilbert Morgan Smith (6 January 1885, Beloit, Wisconsin – 11 July 1959) was a botanist and phycologist, who worked primarily on the algae. He was best known for his books, particularly the ''Freshwater Algae of the United States'', the ''Marine Algae of the Monterey Peninsula'' and the two volumes of '' Cryptogamic Botany''. Career Smith was born on 6 January 1885 to Elizabeth Mayher Smith and Erastus G. Smith in Beloit, Wisconsin, where his father was Professor of Chemistry at the College. His parents were both born in Massachusetts and educated there, at Mt. Holyoke College and Amherst College respectively. Smith attended Beloit College, where he concentrated on botany and chemistry, and graduated in 1907. He taught science at the high school in Stoughton, Wisconsin for the next two years, before beginning graduate studies at the University of Wisconsin in 1909, where he started work on the algal genus '' Oedogonium''. He interrupted his studies for a one-year teaching a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Principle Of Priority
Priority is a principle in Taxonomy (biology), biological taxonomy by which a valid scientific name is established based on the oldest available name. It is a decisive rule in Botanical nomenclature, botanical and zoological nomenclature to recognise the first Binomial nomenclature, binomial name (also called ''binominal name'' in zoology) given to an organism as the correct and acceptable name. The purpose is to select one scientific name as a stable one out of two or more alternate names that often exist for a single species. The ''International Code of Nomenclature for algae, fungi, and plants'' (ICN) defines it as: "A right to precedence established by the date of valid publication of a legitimate name or of an earlier homonym, or by the date of designation of a type." Basically, it is a scientific procedure to eliminate duplicate or multiple names for a species, for which Lucien Marcus Underwood called it "the principle of outlaw in nomenclature". History The principle of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Subgenera
In biology, a subgenus ( subgenera) is a taxonomic rank directly below genus. In the International Code of Zoological Nomenclature, a subgeneric name can be used independently or included in a species name, in parentheses, placed between the generic name and the specific epithet: e.g. the tiger cowry of the Indo-Pacific, ''Cypraea'' (''Cypraea'') ''tigris'' Linnaeus, which belongs to the subgenus ''Cypraea'' of the genus ''Cypraea''. However, it is not mandatory, or even customary, when giving the name of a species, to include the subgeneric name. In the International Code of Nomenclature for algae, fungi, and plants (ICNafp), the subgenus is one of the possible subdivisions of a genus. There is no limit to the number of divisions that are permitted within a genus by adding the prefix "sub-" or in other ways as long as no confusion can result. Article 4 The secondary ranks of section and series are subordinate to subgenus. An example is ''Banksia'' subg. ''Isostylis'', a sub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Polyphyletic
A polyphyletic group is an assemblage that includes organisms with mixed evolutionary origin but does not include their most recent common ancestor. The term is often applied to groups that share similar features known as Homoplasy, homoplasies, which are explained as a result of convergent evolution. The arrangement of the members of a polyphyletic group is called a polyphyly .. [Source for pronunciation.] It is contrasted with monophyly and paraphyly. For example, the biological characteristic of warm-bloodedness evolved separately in the ancestors of mammals and the ancestors of birds; "warm-blooded animals" is therefore a polyphyletic grouping. Other examples of polyphyletic groups are algae, C4 photosynthesis, C4 photosynthetic plants, and Xenarthra#Evolutionary relationships, edentates. Many taxonomists aim to avoid homoplasies in grouping taxa together, with a goal to identify and eliminate groups that are found to be polyphyletic. This is often the stimulus for major re ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
George Stephen West
George Stephen West (20 April 1876 – 7 August 1919), ARCS, FLS, was a British botanist, a specialist in phycology and protistology, a botanical illustrator and a writer. With his father, botanist William West (West, 1848–1914), he collaborated on numerous scientific books. West's brother was the botanist William West Jr (W. West, 1875–1901), who assisted their father with fieldwork. West was professor of natural history at the Royal Agricultural College at Cirencester, then was based for the rest of his life at the University of Birmingham, where he was elected Mason Professor of Botany, following the retirement of William Hillhouse. While there, he enlarged the botany department. One of his students was Muriel Bristol. He was a Fellow of the Linnean Society of London, and president of Birmingham Natural History and Philosophical Society. West was married with two sons who were young children when he died at age 43 of double pneumonia. He left behind numerous scien ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Scenedesmus
''Scenedesmus'' is a genus of green algae, in the class Chlorophyceae. They are colonial and non-motile. They are one of the most common components of phytoplankton in freshwater habitats worldwide. Taxonomy The starting point of ''Scenedesmus'' and related algae is in 1820, when Pierre Jean François Turpin observed these algae under a microscope. He classified them under the diatom genus '' Achnanthes''; later authors moved them to different groups, until it was finally classified as a green alga. The name comes from the Greek roots ''skene'', meaning "tent" or "awning", and ''desmos'', meaning "bond". Currently, there are 74 taxonomically accepted species of ''Scenedesmus''. Additionally, several subgenera have been identified, but vary according to the source. Hegewald denotes ''Acutodesmus'', '' Desmodesmus'', and ''Scenedesmus'' as the three major categories. ''Acutodesmus'' is characterized as having acute cell poles, while ''Desmodesmus'' and ''Scenedesmus'' have obtuse/t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Robert Hippolyte Chodat
Robert Hippolyte Chodat (4 June 1865, Moutier – 28 April 1934) was a Swiss botanist and phycologist who was a professor and director of the botanical institute at the University of Geneva. He studied medicine and botany at Geneva, where he was later a lecturer of pharmacy. In 1889 he attained the title of associate professor, two years later becoming a full professor of medical and pharmaceutical botany. From 1900 onward, he taught classes in general and systematic botany. In 1908 he was appointed rector at the University of Geneva. Chodat was a leading authority of the botanical family Polygalaceae. In 1914, with Emil Hassler (1864–1937), he collected plants in Región Oriental of Paraguay. He was made Chevalier de la Légion d'Honneur in 1909. He was winner of the 1933 Linnean Medal. Selected publications * ''Monographia Polygalacearum'', vol.1 1891, vol.2 1893. * 1898–1907 : ''Plantae Hasslerianae'' (with Emil Hassler).RAMELLA, L. & P. PERRET (2003b). Editores, aut ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Biological Soil Crust
Biological soil crusts, often abbreviated as biocrusts, are communities of living organisms inhabiting the surface of soils in arid and semi-arid ecosystems, which form stable aggregates of soil particles in a thin layer millimeters to centimeters thick. They are found throughout the world with varying species composition and cover depending on topography, soil characteristics, climate, plant community, microhabitats, and disturbance regimes. An estimated 12% of Earth's surface is covered by biocrusts. Biological soil crusts perform important ecological roles including carbon fixation, nitrogen fixation and soil stabilization; they alter soil albedo and water relations and affect germination and nutrient levels in vascular plants. They can be damaged by fire, recreational activity, grazing and other disturbances and can require long time periods to recover composition and function. Other names for biological soil crusts include ''cryptogamic'', ''microbiotic'', ''microphytic'', o ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tetradesmus Lagerheimii
''Tetradesmus lagerheimii'' is a green alga in the family Scenedesmaceae Scenedesmaceae is a family of green algae in the order Sphaeropleales. ''Scenedesmus'' algae are commonly found in freshwater plankton. The former family Coelastraceae is considered a synonym of Scenedesmaceae. The family has existed since at .... It is also known by its synonym, ''Scenedesmus acuminatus''. ''Tetradesmus lagerheimii'' forms colonies of two, four or eight cells in a single row, with cells arranged linearly or in a somewhat zig-zag fashion. The colony is typically curved, semicircular, or contorted. Cells are spindle-shaped, arc-like, or sigmoid, 9.2–34.5(–40) μm long and 2–5.5 μm wide; the outermost side is concave; both ends taper to a point. It is a very common species, and is found in a variety of freshwater habitats. References Sphaeropleales Chlorophyta species {{Chlorophyceae-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fresh Water
Fresh water or freshwater is any naturally occurring liquid or frozen water containing low concentrations of dissolved salt (chemistry), salts and other total dissolved solids. The term excludes seawater and brackish water, but it does include non-salty mineral water, mineral-rich waters, such as chalybeate springs. Fresh water may encompass frozen water, frozen and meltwater in ice sheets, ice caps, glaciers, snowfields and icebergs, natural precipitations such as rainfall, snowfall, hail/ice pellets, sleet and graupel, and surface runoffs that form inland bodies of water such as wetlands, ponds, lakes, rivers, streams, as well as groundwater contained in aquifers, subterranea (geography), subterranean subterranean river, rivers and underground lake, lakes. Water is critical to the survival of all living organisms. Many organisms can thrive on salt water, but the great majority of vascular plants and most insects, amphibians, reptiles, mammals and birds need fresh water to sur ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
National Center For Biotechnology Information
The National Center for Biotechnology Information (NCBI) is part of the National Library of Medicine (NLM), a branch of the National Institutes of Health (NIH). It is approved and funded by the government of the United States. The NCBI is located in Bethesda, Maryland, and was founded in 1988 through legislation sponsored by US Congressman Claude Pepper. The NCBI houses a series of databases relevant to biotechnology and biomedicine and is an important resource for bioinformatics tools and services. Major databases include GenBank for DNA sequences and PubMed, a bibliographic database for biomedical literature. Other databases include the NCBI Epigenomics database. All these databases are available online through the Entrez search engine. NCBI was directed by David Lipman, one of the original authors of the BLAST sequence alignment program and a widely respected figure in bioinformatics. GenBank NCBI had responsibility for making available the GenBank DNA seque ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
