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Lupinus Arcticus
''Lupinus arcticus'' is a species of flowering plant in the Fabaceae, legume family known by the common names Arctic lupine or subalpine lupine. It is native to northwestern North America, where it occurs from Oregon north to Alaska and east to Nunavut.''Lupinus arcticus''. USDA PLANTS Profile. It is a common wildflower in British Columbia.Burton, C. M. and P. J. Burton. (2003) A Manual for Growing and Using Seed from Herbaceous Plants Native to the Northern Interior of British Columbia: ''Lupinus arcticus''. Symbios Research and Rest ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sereno Watson
Sereno Watson (December 1, 1826 in East Windsor Hill, Connecticut – March 9, 1892 in Cambridge, Massachusetts) was an American botanist. Graduating from Yale in 1847 in Biology, he drifted through various occupations until, in California, he joined the Clarence King Expedition and eventually became its expedition botanist. Appointed by Asa Gray as assistant in the Gray Herbarium of Harvard University in 1873, he later became its curator, a position he maintained until his death. Watson was elected a Fellow of the American Academy of Arts and Sciences in 1874, and a member of the National Academy of Sciences in 1889. Works * ''Botany'', in ''Report of the geological exploration of the 40th parallel made ... by Clarence King'', 1871 * * Publications by and about S. Watsoon WorldCat References External linksBiographical sketch at the Gray Herbarium site [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Tundra
In physical geography, tundra () is a type of biome where tree growth is hindered by frigid temperatures and short growing seasons. The term ''tundra'' comes through Russian (') from the Kildin Sámi word (') meaning "uplands", "treeless mountain tract". There are three regions and associated types of tundra: Arctic tundra, alpine tundra, and Antarctic tundra. Tundra vegetation is composed of dwarf shrubs, sedges, grasses, mosses, and lichens. Scattered trees grow in some tundra regions. The ecotone (or ecological boundary region) between the tundra and the forest is known as the tree line or timberline. The tundra soil is rich in nitrogen and phosphorus. The soil also contains large amounts of biomass and decomposed biomass that has been stored as methane and carbon dioxide in the permafrost, making the tundra soil a carbon sink. As global warming heats the ecosystem and causes soil thawing, the permafrost carbon cycle accelerates and releases much of these soil-contained g ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Alaska
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] |
Flora Of Western Canada
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 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Flora Of Northern Canada
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] |
Lupinus
''Lupinus'', commonly known as lupin, lupine, or regionally bluebonnet etc., is a genus of plants in the legume family Fabaceae. The genus includes over 199 species, with centers of diversity in North and South America. Smaller centers occur in North Africa and the Mediterranean. They are widely cultivated, both as a food source and as ornamental plants, but are invasive to some areas. Description The species are mostly herbaceous perennial plants tall, but some are annual plants and a few are shrubs up to tall. An exception is the ''chamis de monte'' (''Lupinus jaimehintoniana'') of Oaxaca in Mexico, which is a tree up to tall. Lupins have soft green to grey-green leaves which may be coated in silvery hairs, often densely so. The leaf blades are usually palmately divided into five to 28 leaflets, or reduced to a single leaflet in a few species of the southeastern United States and eastern South America. The flowers are produced in dense or open whorls on an erect spik ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ground Squirrel
Ground squirrels are members of the squirrel family of rodents (Sciuridae), which generally live on or in the ground, rather than trees. The term is most often used for the medium-sized ground squirrels, as the larger ones are more commonly known as marmots (genus ''Marmota'') or prairie dogs, while the smaller and less bushy-tailed ground squirrels tend to be known as chipmunks (genus ''Tamias''). Together, they make up the "marmot tribe" of squirrels, Marmotini, a division within the large and mainly ground squirrel subfamily Xerinae, and containing six living genera. Well-known members of this largely Holarctic group are the marmots (''Marmota''), including the American groundhog, the chipmunks, the susliks (''Spermophilus''), and the prairie dogs (''Cynomys''). They are highly variable in size and habitus, but most are remarkably able to rise up on their hind legs and stand fully erect comfortably for prolonged periods. They also tend to be far more gregarious than other sq ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Snowshoe Hare
The snowshoe hare (''Lepus americanus''), also called the varying hare or snowshoe rabbit, is a species of hare found in North America. It has the name "snowshoe" because of the large size of its hind feet. The animal's feet prevent it from sinking into the snow when it hops and walks. Its feet also have fur on the soles to protect it from freezing temperatures. For camouflage, its fur turns white during the winter and rusty brown during the summer. Its flanks are white year-round. The snowshoe hare is also distinguishable by the black tufts of fur on the edge of its ears. Its ears are shorter than those of most other hares. In summer, it feeds on plants such as grass, ferns, and leaves; in winter, it eats twigs, the bark from trees, and plants and, similar to the Arctic hare, has been known to occasionally eat dead animals. It can sometimes be seen feeding in small groups. This animal is mainly active at night and does not hibernate. The snowshoe hare may have up to four litter ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sparteine
Sparteine is a class 1a antiarrhythmic agent; a sodium channel blocker. It is an alkaloid and can be extracted from scotch broom. It is the predominant alkaloid in ''Lupinus mutabilis'', and is thought to chelate the bivalent cations calcium and magnesium. It is not FDA approved for human use as an antiarrhythmic agent, and it is not included in the Vaughan Williams classification of antiarrhythmic drugs. It is also used as a chiral ligand in organic chemistry, especially in syntheses involving organolithium reagents. Biosynthesis Sparteine is a lupin alkaloid containing a tetracyclic bis-quinolizidine ring system derived from three C5 chains of lysine, or more specifically, L-lysine. The first intermediate in the biosynthesis is cadaverine, the decarboxylation product of lysine catalyzed by the enzyme lysine decarboxylase (LDC). Three units of cadaverine are used to form the quinolizidine skeleton. The mechanism of formation has been studied enzymatically, as well as with ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Neurotoxin
Neurotoxins are toxins that are destructive to nerve tissue (causing neurotoxicity). Neurotoxins are an extensive class of exogenous chemical neurological insultsSpencer 2000 that can adversely affect function in both developing and mature nervous tissue.Olney 2002 The term can also be used to classify endogenous compounds, which, when abnormally contacted, can prove neurologically toxic. Though neurotoxins are often neurologically destructive, their ability to specifically target neural components is important in the study of nervous systems. Common examples of neurotoxins include lead, ethanol (drinking alcohol), glutamate,Choi 1987 nitric oxide, botulinum toxin (e.g. Botox), tetanus toxin,Simpson 1986 and tetrodotoxin. Some substances such as nitric oxide and glutamate are in fact essential for proper function of the body and only exert neurotoxic effects at excessive concentrations. Neurotoxins inhibit neuron control over ion concentrations across the cell membrane, or com ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Radiocarbon Dating
Radiocarbon dating (also referred to as carbon dating or carbon-14 dating) is a method for determining the age of an object containing organic material by using the properties of radiocarbon, a radioactive isotope of carbon. The method was developed in the late 1940s at the University of Chicago by Willard Libby. It is based on the fact that radiocarbon () is constantly being created in the Earth's atmosphere by the interaction of cosmic rays with atmospheric nitrogen. The resulting combines with atmospheric oxygen to form radioactive carbon dioxide, which is incorporated into plants by photosynthesis; animals then acquire by eating the plants. When the animal or plant dies, it stops exchanging carbon with its environment, and thereafter the amount of it contains begins to decrease as the undergoes radioactive decay. Measuring the amount of in a sample from a dead plant or animal, such as a piece of wood or a fragment of bone, provides information that can be used to calc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Oldest Viable Seed
There have been several seeds known at different times as the oldest viable seed. Dormancy allows seeds to survive for extended periods, which can aid in seed dispersal and spread out the growth and establishment of seedlings, increasing the likelihood that some of the next generations survive if conditions are not suitable for seedling establishment. Over time, seeds lose viability which is the ability to initiate metabolic activity, cellular growth, and germination. Seeds have many cells and tissues that die over time, and these deaths can be delayed or increased by environmental conditions the seed experiences. Very generally, small seeds, especially from weedy species and annuals are more likely to remain viable in the soil longer than larger perennial seeds. The seeds of some aquatic plants also may remain viable longer in mud because their viability is aided by the aquatic environment which remains cool and moist. Carbon-dated *The oldest seed that has grown into a via ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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