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American Chestnut
The American chestnut (''Castanea dentata'') is a large, fast-growing deciduous tree of the Fagaceae, beech family native to eastern North America. As is true of all species in the genus ''Chestnut, Castanea'', the American chestnut produces Bur, burred fruit with edible nuts. The American chestnut was once common in its Appalachian Mountains, Appalachian Mountain range and was a Dominance (ecology), dominant species in the oak-chestnut forest region of its central and southern range. During the early to mid-20th century, American chestnut trees were devastated by chestnut blight, a fungal disease that came from Castanea crenata, Japanese chestnut trees that were introduced into North America from Japan. It is estimated that the blight killed between three and four billion American chestnut trees in the first half of the 20th century, beginning in 1904.Griffin, Gary"Recent advances in research and management of chestnut blight on American chestnut" Phytopathology (journal), Phyto ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Deciduous
In the fields of horticulture and botany, the term deciduous () means "falling off at maturity" and "tending to fall off", in reference to trees and shrubs that seasonally shed Leaf, leaves, usually in the autumn; to the shedding of petals, after flowering; and to the shedding of ripe fruit. The antonym of deciduous in the botanical sense is evergreen. Generally, the term "deciduous" means "the dropping of a part that is no longer needed or useful" and the "falling away after its purpose is finished". In plants, it is the result of natural processes. "Deciduous" has a similar meaning when referring to animal parts, such as deciduous antlers in deer, deciduous teeth (baby teeth) in some mammals (including humans); or decidua, the uterine lining that sheds off after birth. Botany In botany and horticulture, deciduous plants, including trees, shrubs and herbaceous perennials, are those that lose all of their Leaf, leaves for part of the year. This process is called abscission. I ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Triticum Aestivum
Common wheat (''Triticum aestivum''), also known as bread wheat, is a cultivated wheat species. About 95% of wheat produced worldwide is common wheat; it is the most widely grown of all crops and the cereal with the highest monetary yield. Taxonomy Numerous forms of wheat have evolved under human selection. This diversity has led to confusion in the naming of wheats, with names based on both genetic and morphological characteristics. List of common cultivars * Albimonte * Manital * Shirley * Hilliard Phylogeny Bread wheat is an allohexaploid a combination of six sets of chromosomes from different species. Of the six sets of chromosomes, four come from emmer (''Triticum turgidum'', itself a tetraploid) and two from ''Aegilops tauschii'' (a wild diploid goatgrass). Wild emmer arose from an even earlier ploidy event, a tetraploidy between two diploids, wild einkorn (''T. urartu'') and '' A. speltoides'' (another wild goatgrass). Free-threshing wheat is closely related ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castanea Pumila
''Castanea pumila'', commonly known as the Allegheny chinquapin, American chinquapin (from the Powhatan language, Powhatan) or dwarf chestnut, is a species of chestnut native to the southeastern United States. The native range is from Massachusetts and New York (state), New York to Maryland and extreme southern New Jersey and southeast Pennsylvania south to central Florida, west to eastern Texas, and north to southern Missouri and Kentucky. The plant's habitat is dry sandy and rocky uplands and ridges mixed with oak and hickory to 1000 m elevation. It grows best on well-drained soils in full sun or partial shade. Description It is a spreading shrub or small tree, reaching in height at maturity. The Bark (botany), bark is red- or gray-brown and slightly furrowed into scaly plates. The leaf, leaves are simple, alternately arranged, narrowly elliptical or lanceolate, yellow-green above and paler and finely hairy on the underside. Each leaf is long by wide with parallel side veins ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
All Things Considered
''All Things Considered'' (''ATC'') is the flagship news program on the American network National Public Radio (NPR). It was the first news program on NPR, premiering on May 3, 1971. It is broadcast live on NPR affiliated stations in the United States, and worldwide through several different outlets, formerly including the NPR Berlin station in Germany. ''All Things Considered'' and ''Morning Edition'' were the highest rated public radio programs in the United States in 2002 and 2005. The show combines news, analysis, commentary, interviews, and special features, and its segments vary in length and style. ''ATC'' airs weekdays from 4:00 p.m. to 6:00 p.m. Eastern Time (live) or Pacific Time (recorded with some updates; in Hawaii it airs as a fully recorded program) or from 3:00 p.m. to 5:00 p.m. Central Time. ''ATC's'' weekend counterpart, ''Weekend Edition'', airs on Saturdays and Sundays. Background ''ATC'' programming combines news, analysis, commentary, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Diameter
In geometry, a diameter of a circle is any straight line segment that passes through the centre of the circle and whose endpoints lie on the circle. It can also be defined as the longest Chord (geometry), chord of the circle. Both definitions are also valid for the diameter of a sphere. In more modern usage, the length d of a diameter is also called the diameter. In this sense one speaks of diameter rather than diameter (which refers to the line segment itself), because all diameters of a circle or sphere have the same length, this being twice the radius r. :d = 2r \qquad\text\qquad r = \frac. The word "diameter" is derived from (), "diameter of a circle", from (), "across, through" and (), "measure". It is often abbreviated \text, \text, d, or \varnothing. Constructions With straightedge and compass, a diameter of a given circle can be constructed as the perpendicular bisector of an arbitrary chord. Drawing two diameters in this way can be used to locate the center of ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circumference
In geometry, the circumference () is the perimeter of a circle or ellipse. The circumference is the arc length of the circle, as if it were opened up and straightened out to a line segment. More generally, the perimeter is the curve length around any closed figure. Circumference may also refer to the circle itself, that is, the Locus (geometry), locus corresponding to the Edge (geometry), edge of a Disk (geometry), disk. The is the circumference, or length, of any one of its great circles. Circle The circumference of a circle is the distance around it, but if, as in many elementary treatments, distance is defined in terms of straight lines, this cannot be used as a definition. Under these circumstances, the circumference of a circle may be defined as the Limit (mathematics), limit of the perimeters of inscribed regular polygons as the number of sides increases without bound. The term circumference is used when measuring physical objects, as well as when considering abstrac ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Eudicots
The eudicots or eudicotyledons are flowering plants that have two seed leaves (cotyledons) upon germination. The term derives from ''dicotyledon'' (etymologically, ''eu'' = true; ''di'' = two; ''cotyledon'' = seed leaf). Historically, authors have used the terms tricolpates or non-magnoliid dicots. The current botanical terms were introduced in 1991, by evolutionary botanist James A. Doyle and paleobotanist Carol L. Hotton, to emphasize the later evolutionary divergence of tricolpate dicots from earlier, less specialized, dicots. Scores of familiar plants are eudicots, including many commonly cultivated and edible plants, numerous trees, tropicals and ornamentals. Among the most well-known eudicot genera are those of the sunflower (''Helianthus''), dandelion (''Taraxacum''), forget-me-not ('' Myosotis''), cabbage ('' Brassica''), apple (''Malus''), buttercup ('' Ranunculus''), maple ('' Acer'') and macadamia (''Macadamia''). Most leafy, mid-latitude trees are also classi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Hardwood
Hardwood is wood from Flowering plant, angiosperm trees. These are usually found in broad-leaved temperate and tropical forests. In temperate and boreal ecosystem, boreal latitudes they are mostly deciduous, but in tropics and subtropics mostly evergreen. Hardwood (which comes from angiosperm trees) contrasts with softwood (which is from gymnosperm trees). Characteristics Hardwoods are produced by Flowering plant, angiosperm trees that reproduce by flowers, and have broad leaves. Many species are deciduous. Those of temperate regions lose their leaves every autumn as temperatures fall and are dormant in the winter, but those of tropical regions may shed their leaves in response to seasonal or sporadic periods of drought. Hardwood from deciduous species, such as oak, normally shows annual dendrochronology, growth rings, but these may be absent in some tropical timber, tropical hardwoods. Hardwoods have a more complex structure than softwoods and are often much slower growing ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castanea Dentata
The American chestnut (''Castanea dentata'') is a large, fast-growing deciduous tree of the beech family native to eastern North America. As is true of all species in the genus '' Castanea'', the American chestnut produces burred fruit with edible nuts. The American chestnut was once common in its Appalachian Mountain range and was a dominant species in the oak-chestnut forest region of its central and southern range. During the early to mid-20th century, American chestnut trees were devastated by chestnut blight, a fungal disease that came from Japanese chestnut trees that were introduced into North America from Japan. It is estimated that the blight killed between three and four billion American chestnut trees in the first half of the 20th century, beginning in 1904.Griffin, Gary"Recent advances in research and management of chestnut blight on American chestnut" Phytopathology 98:S7. ''www.apsnet.org'', 2008. Retrieved January 12, 2016.Hebard, F.V"The American Chestnut Fou ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Backcrossing
Backcrossing is a crossing of a hybrid with one of its parents or an individual genetically similar to its parent, to achieve offspring with a genetic identity closer to that of the parent. It is used in horticulture, animal breeding, and production of gene knockout organisms. Backcrossed hybrids are sometimes described with acronym "BC"; for example, an F1 hybrid crossed with one of its parents (or a genetically similar individual) can be termed a BC1 hybrid, and a further cross of the BC1 hybrid to the same parent (or a genetically similar individual) produces a BC2 hybrid. Plants Advantages * If the recurrent parent is an elite genotype, at the end of the backcrossing programme, an elite genotype is recovered. * As no "new" recombination results, the elite combination is not lost. Disadvantages * It works poorly for quantitative traits. * It is more restricted for recessive traits. * In practice, sections of genome from the nonrecurrent parents are often still present a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Castanea Mollissima
''Castanea mollissima'', also known as the Chinese chestnut, is an Asian species of chestnut tree in the family Fagaceae. Description It is a deciduous tree growing to tall with a broad crown. The leaves are alternate, simple, long and broad, with a toothed margin. The flowers are produced in catkins long, with the female flowers at the base of the catkin and males on the rest. The fruit is a densely spiny cupule diameter, containing two or three glossy brown nuts; these are diameter on wild trees. The scientific name ''mollissima'' derives from the softly downy shoots and young leaves. Taxonomy Synonyms: ''Castanea bungeana'' Blume; ''C. duclouxii'' Dode; ''C. fargesii'' Dode; ''C. formosana'' (Hayata) Hayata; ''C. hupehensis'' Dode; ''C. mollissima'' var. ''pendula'' X. Y. Zhou & Z. D. Zhou; ''C. sativa'' Miller var. ''formosana'' Hayata; ''C. sativa'' var.'' mollissima'' (Blume) Pampanini; ''C. vulgaris'' Lamarck var. ''yu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
