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Asplenium × Kentuckiense
''Asplenium'' × ''kentuckiense'', commonly known as Kentucky spleenwort, is a rare, sterile, hybrid fern. It is formed by the crossing of lobed spleenwort ( ''A. pinnatifidum'') with ebony spleenwort ( ''A. platyneuron''). Found intermittently where the parent species grow together in the eastern United States, it typically grows on sandstone cliffs, but is known from other substrates as well. Description ''Asplenium'' × ''kentuckiense'' is a small fern, whose fronds grow in upright, spreading tufts. The stem is a shiny dark brown, the color extending well into the leaf blade. The blades are cut into pinnae near the base, which diminish into lobes in the upper part and eventually to teeth on the sides of a long, drawn-out tip. The fronds are dimorphic, with the fertile fronds much longer and of a different shape than the sterile fronds. The fronds of ''A.'' × ''kentuckiense'', which are long, are closely spaced along a rhizome in diameter. The ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thomas Nuttall
Thomas Nuttall (5 January 1786 – 10 September 1859) was an England, English botany, botanist and zoologist who lived and worked in America from 1808 until 1841. Nuttall was born in the village of Long Preston, near Settle, North Yorkshire, Settle in the West Riding of Yorkshire and spent some years as an apprentice printer in England. Soon after going to the United States he met professor Benjamin Smith Barton in Philadelphia. Barton encouraged his strong interest in natural history. Early explorations in the United States In 1810 he travelled to the Great Lakes and in 1811 travelled on the Astor Expedition led by William Price Hunt on behalf of John Jacob Astor up the Missouri River. Nuttall was accompanied by the English botanist John Bradbury (naturalist), John Bradbury, who was collecting plants on behalf of Liverpool botanical gardens. Nuttall and Bradbury left the party at the trading post with the Arikara Indians in South Dakota, and continued farther upriver with Rams ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Asplenium × Gravesii
''Asplenium'' × ''gravesii'', commonly known as Graves' spleenwort, is a rare, sterile, hybrid fern, named for Edward Willis Graves (1882–1936). It is formed by the crossing of Bradley's spleenwort ( ''A. bradleyi'') with lobed spleenwort ( ''A. pinnatifidum''). It is only found where its parent species are both present; in practice, this proves to be a few scattered sites in the Appalachian Mountains, Shawnee Hills, and Ozarks, reaching perhaps its greatest local abundance around Natural Bridge State Resort Park. Like its parents, it prefers to grow in acid soil in the crevices of sandstone cliffs. Description ''Asplenium'' × ''gravesii'' is a small fern, whose fronds grow in loosely bundled tufts. Its stem below the leaf blade is a shiny purplish-brown, while the green, narrowly triangular blades are cut into pinnae near the base, which diminish into lobes in the upper part. The fronds are monomorphic, showing little or no difference between sterile and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Chromatographic
In chemical analysis, chromatography is a laboratory technique for the separation of a mixture into its components. The mixture is dissolved in a fluid solvent (gas or liquid) called the ''mobile phase'', which carries it through a system (a column, a capillary tube, a plate, or a sheet) on which a material called the ''stationary phase'' is fixed. Because the different constituents of the mixture tend to have different affinities for the stationary phase and are retained for different lengths of time depending on their interactions with its surface sites, the constituents travel at different apparent velocities in the mobile fluid, causing them to separate. The separation is based on the differential partitioning between the mobile and the stationary phases. Subtle differences in a compound's partition coefficient result in differential retention on the stationary phase and thus affect the separation. Chromatography may be preparative or analytical. The purpose of preparativ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Meiosis
Meiosis (; , since it is a reductional division) is a special type of cell division of germ cells in sexually-reproducing organisms that produces the gametes, such as sperm or egg cells. It involves two rounds of division that ultimately result in four cells with only one copy of each chromosome ( haploid). Additionally, prior to the division, genetic material from the paternal and maternal copies of each chromosome is crossed over, creating new combinations of code on each chromosome. Later on, during fertilisation, the haploid cells produced by meiosis from a male and female will fuse to create a cell with two copies of each chromosome again, the zygote. Errors in meiosis resulting in aneuploidy (an abnormal number of chromosomes) are the leading known cause of miscarriage and the most frequent genetic cause of developmental disabilities. In meiosis, DNA replication is followed by two rounds of cell division to produce four daughter cells, each with half the number of chr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Homologous Chromosome
A couple of homologous chromosomes, or homologs, are a set of one maternal and one paternal chromosome that pair up with each other inside a cell during fertilization. Homologs have the same genes in the same loci where they provide points along each chromosome which enable a pair of chromosomes to align correctly with each other before separating during meiosis. This is the basis for Mendelian inheritance which characterizes inheritance patterns of genetic material from an organism to its offspring parent developmental cell at the given time and area. Overview Chromosomes are linear arrangements of condensed deoxyribonucleic acid (DNA) and histone proteins, which form a complex called chromatin. Homologous chromosomes are made up of chromosome pairs of approximately the same length, centromere position, and staining pattern, for genes with the same corresponding loci. One homologous chromosome is inherited from the organism's mother; the other is inherited from the organism ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triploid
Polyploidy is a condition in which the cells of an organism have more than one pair of ( homologous) chromosomes. Most species whose cells have nuclei ( eukaryotes) are diploid, meaning they have two sets of chromosomes, where each set contains one or more chromosomes and comes from each of two parents, resulting in pairs of homologous chromosomes between sets. However, some organisms are polyploid. Polyploidy is especially common in plants. Most eukaryotes have diploid somatic cells, but produce haploid gametes (eggs and sperm) by meiosis. A monoploid has only one set of chromosomes, and the term is usually only applied to cells or organisms that are normally diploid. Males of bees and other Hymenoptera, for example, are monoploid. Unlike animals, plants and multicellular algae have life cycles with two alternating multicellular generations. The gametophyte generation is haploid, and produces gametes by mitosis, the sporophyte generation is diploid and produces spores by ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Guard Cell
Guard cells are specialized plant cells in the epidermis of leaves, stems and other organs that are used to control gas exchange. They are produced in pairs with a gap between them that forms a stomatal pore. The stomatal pores are largest when water is freely available and the guard cells turgid, and closed when water availability is critically low and the guard cells become flaccid. Photosynthesis depends on the diffusion of carbon dioxide (CO2) from the air through the stomata into the mesophyll tissues. Oxygen (O2), produced as a byproduct of photosynthesis, exits the plant via the stomata. When the stomata are open, water is lost by evaporation and must be replaced via the transpiration stream, with water taken up by the roots. Plants must balance the amount of CO2 absorbed from the air with the water loss through the stomatal pores, and this is achieved by both active and passive control of guard cell turgor pressure and stomatal pore size.Schroeder JI, Kwak JM, & Allen GJ ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Herb Wagner
Warren Herbert Wagner Jr. (August 29, 1920 – January 8, 2000) was an eminent American botanist who was trained at Berkeley with E.B. Copeland and lived most of his professional career in Michigan. History Wagner was instructed in the ways of plant microphotograph and embryology by Marion S. Cave. Wagner was a longtime faculty member at the University of Michigan. He was most respected among his colleagues and students for his genius in discerning and articulating the differences in form between plant species in the context of their variation with environmental factors. He developed, in the early 1960s, the first algorithm for discerning phylogenetic relationships among species based upon their respective character states observed over a set of characters. This work was honored by James Farris and Arnold Kluge in their later appellation of related algorithms as "Wagner parsimony." Wagner became a pteridologist later in life, specializing in ferns, especially the Botrychi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Franklin Sumner Earle
Franklin Sumner Earle (September 4, 1856 – January 31, 1929) was an American mycologist who specialized in the diseases and cultivation of sugar cane. He was the first mycologist to work at the New York Botanical Garden, and was the author of ''The Genera of North American Gill Fungi''. Life Frankin Sumner Earle was born in Dwight, Illinois, on September 4, 1856, to Parker Earle and Melanie Tracy. He spent much of his early youth at the Earle farm. Later he attended the University of Illinois at Urbana–Champaign sporadically in the 1880s, but never earned a degree. He studied with the mycologist Thomas Jonathan Burrill. Soon after college, Earle served as the superintendent of the Mississippi Agriculture Experiment Station (1892–1895). Soon after that Earle worked as a biologist and horticulturist of the Alabama Agriculture Experiment Station (1895–1900). Earle worked as an Assistant Curator in charge of mycological collections at the New York Botanical Garden in 1901. H ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Edgar T
Edgar is a commonly used English given name, from an Anglo-Saxon name ''Eadgar'' (composed of '' ead'' "rich, prosperous" and ''gar'' "spear"). Like most Anglo-Saxon names, it fell out of use by the later medieval period; it was, however, revived in the 18th century, and was popularised by its use for a character in Sir Walter Scott's ''The Bride of Lammermoor'' (1819). People with the given name * Edgar the Peaceful (942–975), king of England * Edgar the Ætheling (c. 1051 – c. 1126), last member of the Anglo-Saxon royal house of England * Edgar of Scotland (1074–1107), king of Scotland * Edgar Angara, Filipino lawyer * Edgar Barrier, American actor * Edgar Baumann, Paraguayan javelin thrower * Edgar Bergen, American actor, radio performer, ventriloquist * Edgar Berlanga, American boxer * Edgar H. Brown, American mathematician * Edgar Buchanan, American actor * Edgar Rice Burroughs, American author, creator of ''Tarzan'' * Edgar Cantero, Spanish author in Catalan, Sp ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Rowan County, Kentucky
Rowan County (, ) is a County (United States), county located in the northeastern part of the U.S. state of Kentucky, in the Eastern Kentucky Coalfield region. As of the 2020 United States census, 2020 census, the population was 24,662. Its county seat is Morehead, Kentucky, Morehead. The county was created in 1856 from parts of Fleming and Morgan counties, and named after John Rowan (politician), John Rowan, who represented Kentucky in the United States House of Representatives, House of Representatives and the United States Senate, Senate. With regard to the sale of alcoholic beverages, alcohol, it is classified as a moist county in which alcohol sales are prohibited, but unlike a dry county, it contains a "wet" city, Morehead, where packaged alcohol sales are allowed. History It is believed that Rowan County was first explored by those of European descent in 1773 by a party of surveyors from Pennsylvania. The first settlement was established in Farmers, Kentucky, Farmers, a t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Calloway County, Kentucky
Calloway County is a county located in the southwest part of the U.S. Commonwealth of Kentucky. As of the 2020 census, the population was 37,103. Its county seat is Murray. The county was founded in November 1822 and named for Colonel Richard Callaway, one of the founders of Boonesborough. Calloway County comprises the Murray, KY Micropolitan Statistical Area. Calloway County is a moist county: the sale of alcohol in the county is prohibited, with the exception of the city of Murray. History Calloway County was created in 1822 from land taken from Hickman County. The courthouse was built in 1823. A fire at the courthouse in 1906 caused the almost complete destruction of the county records. Calloway county was named after Richard Callaway. Geography According to the United States Census Bureau, the county has a total area of , of which is land and (6.3%) is water. Adjacent counties * Marshall County (north) * Trigg County (northeast) * Stewart County, Tennessee (sout ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
