. Pith , br 2. Protoxylem , br 3. Xylem I, br 4. Phloem I, br 5. Sclerenchyma bast fibre , br 6. Cortex botany Cortex , br 7. Epidermis botany Epidermis In vascular plant s, phloem is the living Biological ... where needed. In tree s, the phloem is the innermost layer of the bark , hence the name, derived from the Greek language Greek word polytonic wikt phloos bark . The phloem is concerned mainly ... phloem and companion cells ref http www.hydroponicist.com Winterborne J, 2005. Hydroponics Indoor Horticulture ref Phloem tissue consists of conducting cells, generally called sieve elements parenchyma ... primitive of the two main conducting cell types in phloem, and are found in most seedless vascular plants ... sieve element found in the phloem of angiosperms. ref name Raven et al. 1992 cite book last Raven first ... Other parenchyma cells within the phloem are generally undifferentiated and used for food storage. ref name Raven et al. 1992 Supportive cells Although its primary function is fluid transport, phloem ... xylem which is composed primarily of dead cells , the phloem is composed of still living cells that transport ... proposed by Ernst M nch in 1930 that explained the mechanism of phloem translocation. ref cite ... s of the phloem at a source, such as a leaf , creates a diffusion diffusion gradient that draws water into the cells. Movement occurs by bulk flow phloem sap moves from sugar source s to sugar sinks ... s are sugar sources, and the plant s many growing areas are sugar sinks. The movement in phloem ... the phloem is driven by positive hydrostatic pressure s. This process is termed translocation , and is accomplished by a process called phloem loading and unloading . Cells in a sugar source load a sieve ... opposite effect. Some plants, however, appear not to load phloem by active transport. In these cases ... conference author Turgeon, R year 1991 title Symplastic phloem loading and the sink source transition in leaves a model booktitle Recent Advances Phloem Transport and Assimilate Compartmentation editor ... more details
of phloem are connected end to end, just as the sections of a pipe might be. As the plant grows ... include both xylem and phloem, as well as supporting and protective cells. In plant stem stems and root s, the xylem typically lies closer to the interior of the stem with phloem towards the exterior of the stem. In the stems of some Asteriidae dicot s, there may be phloem located inwardly from the xylem as well. Between the xylem and phloem is a meristem called the vascular cambium . This tissue divides off cell biology cell s that will be become additional xylem and phloem. This growth ... a cork cambium that develops among the phloem. The cork cambium gives rise to thickened cork tissue ... the upper side , and phloem is oriented toward the abaxial surface of the leaf. This is why aphid s are typically found on the underside of the leaves rather than on the top, since the phloem transports ... date August 2011 See also Xylem Phloem Cork cambium Vascular cambium Vascular plant Stele biology External ... more details
in phloem is bidirectional, whereas, in xylem cells, it is unidirectional upward . Developement After ..., movement through the phloem is driven by positive hydrostatic pressure s. This process is termed translocation , and is accomplished by a process called phloem loading and unloading . Cells ... the hypothesis. Firstly, there is an exudation of solution from the phloem when the stem is cut ... function of phloem, indicating that the phloem sap is under pressure. Secondly, concentration gradients ... cells. Hence, the hypothesis neglects the living nature of phloem. Moreover, it is found that amino ... inhibitors are two defects of the hypothesis. Other theories Some plants appear not to load phloem ... Turgeon . ref cite conference author Turgeon, R year 1991 title Symplastic phloem loading and the sink source transition in leaves a model booktitle Recent Advances Phloem Transport and Assimilate ... through wider plasmodesmata into the sieve tube element. The symplastic phloem loading is confined ... apoplastic phloem loading is viewed as more advanced, as it is found in the later evolved plants ... hormone s, and even messenger RNA s are transported in the phloem through sieve tube element s. References ... more details
Image Celery cross section.jpg thumb Cross section of celery stalk, showing vascular bundles, which include both phloem and xylem A vascular bundle is a part of the transport system in vascular plant s. The transport itself happens in vascular tissue , which exists in two forms xylem and phloem . Both these tissues are present in a vascular bundle, which in addition will include supporting and protective tissues. Also, it is a vein in the leaf that contains conducting tissues. The xylem typically lies wiktionary adaxial adaxial with phloem positioned wiktionary abaxial abaxial . In a stem or root this means that the xylem is closer to the centre of the stem or root while the phloem is closer to the exterior. In a leaf, the adaxial surface of the leaf will usually be the upper side, with the abaxial surface the lower side. This is why aphid s are typically found on the underside of a leaf rather than on the top, since the sugars manufactured by the plant are transported by the phloem, which is closer to the lower surface. The position of vascular bundles relative to each other may vary considerably see Stele biology stele . Bundle sheath cells Bundle sheath cells are photosynthetic cells arranged into tightly packed sheaths around the veins of a leaf. They form a protective covering on leaf veins, and consist of one or more cell layers, usually parenchyma . Loosely arranged mesophyll cells lie between the bundle sheath and the leaf surface. The Calvin cycle is confined to the chloroplasts of these bundle sheath cells in C4 carbon fixation C4 plants . External links Vascular bundles pictured in cross section, by http botweb.uwsp.edu anatomy primaryxylem.htm Curtis, Lersten, and Nowak and http www.sbs.utexas.edu mauseth weblab webchap8phloem chapter 8.htm Mauseth References Campbell, N. A. & Reece, J. B. 2005 . Photosynthesis. Biology 7th ed. . San Francisco Benjamin Cummings. Category Plant anatomy Category Plant physiology Category Tissues cs C vn svazek de Leitb nd ... more details
Multiple issues wikify March 2011 orphan March 2011 The transport of water and nutrient s through the voluminous cortex of the cactus is possible because of the presence of a vascular system exclusive to cacti, the cortical bundle. The cortical bundle emerges radially from the xylem and produces shoots that run tangentially to the cortex, branching extensively and vascularizing every part of the cortex. Because cacti live a long time, the cortical bundles have to function for many years. In every cactus species, the cortical bundles produce secondary phloem s. In very old cortical bundles located at the base of very old shoots, the secondary phloem may attain a thickness of several millimeters. External links http www.cactus art.biz note book Dictionary Dictionary C dictionary cortex.htm http aob.oxfordjournals.org content 70 4 317.abstract http www.sbs.utexas.edu mauseth weblab webchap11stem 11.3 7.htm cactus stub Category Cacti ... more details
Translocation may refer to Chromosomal translocation , in genetics Translocation in plants, transport of food or pesticides through phloem or xylem Protein translocation or protein targeting , a process in protein biosynthesis Translocation wildlife conservation , capture, transport and release or introduction or reintroduction of plants, animals or habitat from one location to another. Bacterial translocation disambig de Translokation es Translocaci n sr Translokacija ur ... more details
context date September 2010 NOTOC Image Stem cross section2.jpg thumb 250px Multiple cross sections of a stem showing vascular cambium and companion cells ref Winterborne J, 2005. Hydroponics Indoor Horticulture http www.hydroponicist.com ref The vascular cambium pl. cambia or cambiums is a part of the morphology biology morphology of plants . It consists of cells that are partly specialized, for the tissues that transport water solutions, but have not reached any of the final forms that occur in their branch of the specialization graph. When these cells have divided and specialized further they make up the secondary vascular tissues , secondary xylem and the secondary phloem . The vascular cambium is a lateral meristem in the vascular tissue of plants. The vascular cambium is the source of both the secondary xylem inwards, towards the pith and the secondary phloem outwards , and is located between these tissues in the stem and root. A few leaf types also have a vascular cambium. ref Ewers, F.W. 1982. Secondary growth in needle leaves of Pinus longaeva bristlecone pine and other conifers Quantitative data. American Journal of Botany 69 1552 1559. http links.jstor.org sici?sici 0002 9122 198211 2F12 69 3A10 3C1552 3ASGINLO 3E2.0.CO 3B2 K ref Origin Vascular cambium arises from the primary meristem, procambium that remains undifferentiated between the primary xylem and primary phloem. Upon maturity, this region known as the fascicular cambium, and the area of cells between the vascular bundles fascicles called pith rays becomes what is called the interfascicular cambium. The fascicular and interfascicular cambiums, therefore, represent a continuous ring which bisects the primary xylem and primary phloem. The vascular cambium then produces secondary xylem on the inside of the ring, and secondary phloem on the outside, pushing the primary xylem and phloem apart. The vascular cambium usually consists of two types of cells Fusiform initials tall cells, wiktionary axial ax ... more details
in which plate like regions of xylem appear in transverse section surrounded by phloem tissue ... originate called leaf gaps . Siphonosteles can be ectophloic phloem present only external to the xylem or they can be amphiphloic with phloem both external and internal to the xylem. Among living plants ... islands of xylem surrounded by phloem. Each of the apparently isolated units of a dictyostele ... can be collateral with the phloem on only one side of the xylem or bicollateral with phloem ... more details
Image Elmphloemnecrosis.jpg thumb Symptoms of Elm Phloem Necrosis Elm Yellows is a phytopathology plant disease of elm trees that is spread by leafhoppers or by root grafts. ref name Elm Yellows Elm Yellows. Elmcare.Com. 19 Mar. 2008 http www.elmcare.com disease elm yellows.htm . ref Elm Yellows, also known as Elm Phloem Necrosis, is very aggressive, with no known cure. Elm Yellows occurs in the Eastern United States and southern Ontario in Canada. It is caused by phytoplasmas which infect the phloem inner bark of the tree. ref name Price Price, Terry. Wilt Diseases. Forestpests.Org. 23 Mar. 2005. 19 Mar. 2008 http www.forestpests.org gfcbook wiltdiseases.html . ref Infection and death of the phloem effectively girdles the tree and stops the flow of water and nutrients. The disease affects both wild growing and cultivated trees. Importance Elms are very important to the American landscape, prized for their unique shade characteristics. Most native elms are susceptible to Elm Yellows and there are few resistant cultivars. ref name Elm Yellows Large, healthy, landscaped elm trees can easily be worth thousands of dollars. Deleted image removed Image elm4.jpg thumb An Elm Tree Penn State University is home to one of the oldest and largest elm stands in the country. Penn State has been battling Dutch Elm Disease for many decades, and the recent introduction of Elm Yellows into the PSU campus poses many threats. ref name Ruskin Ruskin, Paul. Penn State Prepares for Elm Yellows Disease. PSU Live 12 Nov. 2007.19 Mar. 2008 http live.psu.edu story 27225 . ref A tree near the president s house had to be removed and numerous trees in the State College Borough have died or have been removed ... the phloem, which will stop the tree from getting the nutrients it needs. ref name Elm Yellows The phloem is in charge of transportation of nutrients up the tree. Death of the phloem essentially strangles the tree to death. As the phloem is infected, it will change color and take on a wintergreen ... more details
wiktionarypar sap Sap may refer to Plant sap , the fluid transported in xylem cells tracheids or vessel elements or phloem sieve tube elements of a plant Sap village , a village in the Dunajsk Streda District of Slovakia S p , a village in the Hajd Bihar county of Hungary Sap album Sap album , a 1992 EP album by Alice in Chains Sapping , a method of advancing a trench towards an enemy s works Baton law enforcement Sap Sap , a weapon composed of a weighted bag of lead Jolande Sap , Dutch politician See also SAP disambiguation disambig de Saft es Sap hu Sap nl Sap no Sap pt Seiva ... more details
Unreferenced stub auto yes date December 2009 Dephosphorylation is the essential process of removing phosphate groups from an organic compound as adenosine triphosphate ATP by hydrolysis . Its opposite is phosphorylation . It is found in muscle movement as well as many other reactions within the body, as well as reactions in plants . For example, ATP is hydrolysed to adenosine diphosphate ADP with the release of energy, phosphate groups, and ADP in the active transport of sucrose molecules into a phloem vessel in a plant. See also Phosphatase Category Cell biology Category Signal transduction Category Posttranslational modification Category Phosphorus Biochem stub de Dephosphorylierung es Desfosforilaci n pl Defosforylacja ... more details
Liber may refer to Liber , the god of Roman mythology associated with the Greek god Dionysus Freedom disambiguation in Latin and Romanian libero in Italian see also Gratis versus Libre The Latin root for many English words referring to freedom see above , such as Libertarianism liber tarianism , liberalism liber alism , liberty liber ty , Liberia Liber ia free land , and liberation liber ation Phloem , in botany, for which liber is another name In real estate, the book in which a subdivision plat is recorded Liber, Indiana , a small town in the United States Liber musician , a Polish music producer and rapper. disambig ... more details
Image Labeledstemforposter copy new.jpg thumb Flax stem cross section, showing locations of underlying tissues. Ep Epidermis botany epidermis C Cortex botany cortex BF bast fibres P phloem X xylem Pi pith Bast fibre or skin fibre is plant fibre collected from the phloem the inner bark or the skin or bast surrounding the stem of certain, mainly dicotyledon ous, plant s. They support the conductive cells of the phloem and provide strength to the stem. Most of the technically important bast fibres are obtained from herbs cultivated in agriculture, as for instance flax , hemp , or ramie , but also bast fibres from wild plants, as stinging nettle , and trees such as Tilia lime or linden , have been used to some extent. Since the valuable fibres are located in the phloem, they must often be separated from the xylem material woody core , and sometimes also from epidermis botany epidermis . The process for this is called retting , and can be performed by micro organisms either on land nowadays the most important or in water, or by chemicals for instance high pH and chelating agents or by pectin olytic enzyme s. In the phloem bast fibres occur in bundles that are glued together by pectin and calcium ion s. More intense retting separates the fibre bundles into elementary fibres, that can be several centimetres long. Often bast fibres have higher tensile strength than other kinds, and are used in high quality textile s sometimes in blends with cotton or synthetic fibres , rope s, yarn , paper , composite material s and burlap . A special property of bast fibres is that they contain a special structure, the fibre node , that represents a weak point. Seed hairs, such as cotton, do not have nodes. Examples are Jute Hemp Flax Linen Ramie Kenaf Kudzu Nettle Okra Paper Mulberry Roselle hemp Rattan Wisteria Use of bast fibre Bast fibres are processed for use in carpet yarn , rope , geotextile netting or matting , traditional carpets, burlap hessian or burlap , paper , sacks, etc. Bas ... more details
Unreferenced stub auto yes date December 2009 Orphan date December 2009 Garut Oranges are a fruit variety grown in Indonesia s mountains and hilly areas in Garut Regency at Wanaraja, Samarang and Bayongbong Districts. These locations feature mountains or hilly areas, with highland views of more than 900 m 2,953 ft. above sea level . Many kinds of fruits and vegetable s compete for this growing area. When Indonesia was a Netherlands Dutch colony, Garut Oranges were considered one of Indonesia s most famous exotic fruits. Garut Oranges have a good taste, good coloring, thick skin textures, and good aroma. Crops have been significantly damaged by Citrus Vein Phloem Degeneration CVPD . DEFAULTSORT Garut Orange Fruit Category Citrus Category Fruits originating in Asia Category Flora of Indonesia Agri stub Fruit stub Rutaceae stub ... more details
Unreferenced date October 2008 In botany , a photoassimilate is one of a number of biological compounds formed by Assimilation biology assimilation using light dependent reaction s. This term is most commonly used to refer to the energy storing monosaccharide s produced by photosynthesis in the leaves of plants. Only NADPH, ATP and water are made in the light reactions. Monosaccharides, though generally more complex sugars, are made in the dark reactions.The term light reaction can be confusing as some dark reactions require light to be active. Fact date October 2008 Photoassimilate movement through plants from source to sink using xylem and phloem is of biological significance. This movement is mimicked by many infectious particles namely viroids to accomplish long ranged movement and consequently infection of an entire plant. Category Biomolecules Category Photosynthesis Category Metabolism Category Plant pathogens and diseases botany stub pt Fotoassimilado ... more details
about the German plant physiologist the French conductor and organist Ernst M nch musician Infobox scientist name Ernst M nch image image size caption birth date 1876 birth place death date 1946 death place residence citizenship German nationality German ethnicity field Botany work institutions alma mater doctoral advisor doctoral students known for The Pressure Flow hypothesis in phloem author abbrev bot author abbrev zoo influences influenced prizes religion footnotes Ernst M nch 1876 &ndash 1946 was a Germany German plant physiology plant physiologist who proposed the Pressure Flow Hypothesis in 1926. He worked in Aschaffenburg and Munich with Robert Hartig . He worked in a number of fields including forest pathology , resin production, and fungi. He is best known for the phloem pressure flow hypothesis though. Works Die Stoffbewegungen in der Pflanze , Jena 1930 Beitr ge zur Forstpflanzenz chtung. Versuche einer Auslesez chtung durch Einzelstamm Absaaten bei Fichte. Weitere Beitr ge zur Forstpflanzenz chtung Aus dem wissenschaftlichen Nachlass herausgegeben von Bruno Huber , M nchen 1949 Further reading E. H xtermann Ernst M nch . In Ilse Jahn Hrsg. Geschichte der Biologie. Theorien, Methoden, Institutionen, Kurzbiografien . 3. Auflage, Spektrum Akademischer Verlag, Heidelberg 2000, S. 909 Nachdruck Nikol, Hamburg 2004, ISBN 3 937872 01 9 Heinrich Rubner Ernst M nch . In ders. Hundert bedeutende Forstleute Bayerns 1875 bis 1970 . Mitteilungen aus der Staatsforstverwaltung Bayerns. Bayerisches Staatsministerium f r Ern hrung, Landwirtschaft und Forsten, M nchen 1994, S. 242 243 Persondata Metadata see Wikipedia Persondata . NAME Munch, Ernst ALTERNATIVE NAMES SHORT DESCRIPTION DATE OF BIRTH 1876 PLACE OF BIRTH DATE OF DEATH 1946 PLACE OF DEATH DEFAULTSORT Munch, Ernst Category German botanists Category 1876 births Category 1946 deaths Germany botanist stub de Ernst M nch Forstwissenschaftler ... more details
The unifacial cambium pl. cambia or cambiums produces cells to the interior of its cylinder. These cells differentiate into xylem tissue. Unlike the more common bifacial vascular cambium cambium found in later woody plants , the unifacial cambium does not produce phloem to its exterior. Also in contrast to the bifacial cambium, the unifacial cambium is unable to expand its circumference with anticlinal cell division. Cell elongation provides a limited amount of expansion. Unifacial cambium plant morphology and life cycles The unifacial cambium allowed plants to grow as tall as 50 metres. Lacking secondary phloem, unifacial cambium plants developed alternative strategies to long range nutrient transport. For example, the stems of lycophyte trees were covered in photosynthesizing leaf bases. Due to the limited capacity for circumference growth, unifacial cambium plants had very little wood compared to modern woody plants. Xylem tissue in unifacial cambium plants was particularly structurally efficient. Additional structural support was provided in lycophytes by a special periderm tissue in the outer cortex. Lycophyte trees exhibit determinate growth. These trees appear to have lived for most of their life cycle as a stump , establishing root networks underground, before shooting up rapidly, releasing spores, and dying shortly thereafter. External links http patroklos.earth.northwestern.edu richbarclay PPC Donoghue 2005 Paleobiology KeyInnovMacroevol.pdf Key innovations, convergence, and success macroevolutionary lessons from plant phylogeny , article by Michael J. Donahue from Paleobiology 31 2 , 2005 pdf http www.devoniantimes.org who pages lycopsid.html Devonian Times More About Lycopsids Category Plant physiology Category Plant anatomy botany stub ... more details
Orphan date February 2009 Forisomes are moving protein s occurring in the cells of some plants. Their molecules are about 1 3 m wide and 10 30 m long. They expand and contract anisotropy anisotropically in response to changes of electric field , pH , or concentration of calcium Ca sup 2 sup ions. Unlike most other moving protein s, the change is not dependent on adenosine triphosphate ATP . In the Fabaceae legume plants, forisomes function as valves in sieve tubes of the phloem system, by reversibly changing shape between low volume ordered crystal crystalloid spindles and high volume disordered spherical Protein structure conformations . The change from ordered to disordered conformation involves tripling of the protein s volume, loss of birefringence present in the crystalline phase, 120 radial expansion and 30 longitudinal shrinkage. In i Vicia i it was shown that forisomes are associated to the endoplasmic reticulum at sieve plates . There are evidences that the forisomes s behavior could depend on calcium Ca sup 2 sup changes provoked by Ca sup 2 sup permeable ion channels , located on the endoplasmic reticulum and plasma membrane of sieve elements . ref name Furch cite web url http www.ncbi.nlm.nih.gov pmc articles PMC2729599 title Sieve Element Ca sup 2 sup Channels as Relay Stations between Remote Stimuli and Sieve Tube Occlussion in i Vicia faba i author Alexandra C.U. Furch, Aart J.E. van Bel, Mark D. Fricker, Hubert H. Felle, Maike Fuchs, Jens Hafke year 2009 journal The Plant Cell volume 21 pages 2118 2132 ref Forisomes have possible applications as biomimetic smart material s e.g. valves in microdevices or smart composite material s. References Reflist External links http www.ipam.ucla.edu abstract.aspx?tid 5939 Forisome A smart plant protein inside a phloem system http www.me.wustl.edu ME faculty aqshen smartsystem.pdf Forisome based biomimetic smart materials http www.medgadget.com archives 2006 12 forisome protein.html Forisome Protein, a Key to Bi ... more details
File Orosius orientalis EPG.jpg thumb left The Common Brown Leafhopper Orosius orientalis connected to the EPG electrode The electrical penetration graph or EPG is a system used by biologists to study the interaction of insect s such as aphid s, thrips , and leafhopper s with plant s. Therefore, it can also be used to study the basis of plant virus transmission, host plant selection by insects and the way in which insects can find and feed from the phloem of the plant. It is a simple system consisting of a partial Electronic circuit circuit which is only completed when a species such as aphids, which are the most abundantly studied, inserts its stylet into the plant in order to probe the plant as a suitable host for feeding. The completed circuit is displayed visually as a graph with different waveforms indicating either different insect activities such as saliva excretion or the ingestion of cellular contents or indicating which tissue type has been penetrated i.e. phloem , xylem or mesophyll . So far, around ten different graphical waveforms are known, correlating with different insect plant interaction events. The Circuit The circuit connects to the insect via a 20 m gold wire and to the plant via a copper electrode placed in the soil. The circuit also passes through, normally, a one gigaohm resistor and a 50x amplifier before the results are stored digitally and interpreted by a computer to calculate the final graph. Image EPG circuit.png 600px See also Plant Virus es Epidemiology Aphididae Insect External links http www.epgsystems.eu EPG systems Tjallingii, W.F. 1988 . Electrical recording of stylet penetration activities. In A.K. Minks & P. Harrewijn eds. . Aphids, their biology, natural enemies and control, 95 108. Martin, B. Collar, J.L. Tjallingii, W.F. Fereres, A. 1997 . Intracellular ingestion and salivation may cause the acquisition and inoculation of non persistently transmitted plant viruses. Journal of General Virology, 78, 2701 2705. DEFAULTSOR ... more details
, br 3. en xylem Xylem I, br 4. en phloemPhloem I, br 5. en Sclerenchyma Sclerenchyma en bast fibre ... in other multicellular organisms are vascular tissue in plant s, such as xylem and phloem . Plant ... tissue The primary components of vascular tissue are the xylem and phloem . These transport fluid ... cells mainly occur in hypodermis , pericycle , secondary xylem and phloem. They also occur in endocorp ... complex tissues in vascular plants are xylem , phloem . Xylem Xylem is a chief, conducting tissue of vascular ... and in cross section will look like the spokes of a wheel. PhloemPhloem is an equally important plant tissue as it also is part of the plumbing of a plant. Primarily, phloem carries dissolved ... both xylem and phloem. This usually also includes fibers, parenchyma and ray cells. Sieve tubes are formed ..., the callose and a phloem protein will be moved through the nearest sieve plate where they will form ... to overall plant turgor pressure. Phloem transports food and materials in plants in upwards and downwards ... more details
Unreferenced date September 2007 The pericycle is a cylinder of parenchyma cells that lies just inside the endodermis and is the outer most part of the stele biology stele of plants. Although it is composed of non vascular parenchyma cells, it is still considered part of the vascular cylinder because it arises from the procambium as do the vascular tissues it surrounds. In dicots , it also has the capacity to produce lateral roots . Branch roots arise from this primary meristem tissue. In plants undergoing secondary growth , the pericycle contributes to the vascular cambium often diverging into a cork cambium . Structure A plant tissue characteristic of the roots, located between the endodermis and phloem. It may be of single layer or it may be multilayered. Function In dicot roots, the vascular cambium is completely secondary in origin, and it originates from a portion of pericycle tissue. Since it has the capacity to produce lateral roots, the pericycle also, therefore, regulates the formation of lateral roots. It has been known to often be confused with other parts of the plant. However, its unique ring structure allows it to be more easily identified Past efforts to isolate such tissue have been successful. monocot roots rarely branch, but can, and this branch will originate from the pericycle Category Plant morphology botany stub it Periciclo pl Okolnica botanika pt Periciclo ... more details
Image AnnelageAnn lationGirdling1LilleLamiot3.jpg thumb 300px Girdling in Lille , Northern France Girdling , also called ring barking or ring barking , is the complete removal of a strip of bark consisting of cork cambium,phloem,cambium and going into the xylem from around the entire circumference of either a branch or trunk of a woody plant . Girdling results in the death of wood tissues beyond the damage. A branch completely girdled will fail and when the main trunk of a woody plant is girdled, the entire tree will die, if it cannot regrow and bridge the wound from below. Among the causes of girde are human practices, including forestry , horticulture , and vandalism . Forester s use the practice of girdling to thin forest s and orchardist s use it as a cultural technique to yield larger fruit. Girdling can also be caused by herbivorous mammals feeding on plant bark and by birds and insects, both of which can effectively girdle a tree by boring rows of adjacent holes. Forestry and horticulture Like all plants, trees use two vascular tissue s for transportation of water and nutrients the xylem also known as the wood , and the phloem . Girdling results in the removal of the phloem , and death occurs from the inability of the leaf leaves to transport sugar s primarily sucrose to the root s. In this process, the xylem is left untouched, and the tree can usually still temporarily transport water and minerals from the roots to the leaves until the roots die. Death occurs when the roots can no longer produce adenosine triphosphate ATP and transport nutrients upwards through the xylem . Ring barking techniques have been developed to disrupt or impede sugar transport in phloem, stimulating early flower production and increasing fruiting, and for controlling plant size, reducing the need for pruning. ref Coombs, Blackburn Maze,Cracknell, Bentley 1992 The Complete Book Of Pruning p.23 ISBN 0 7063 7235 2 ref Girdling is a slow process compared to Felling and is often used onl ... more details
Unreferenced date December 2009 Image Stem histology cross section tag.svg thumb right Cross section of a flax plant stem br 1. Endodermis br 2. Protoxylem br 3. Xylem I br 4. Phloem I br 5. Sclerenchyma bast fibre br 6. Cortex br 7. epidermis botany Epidermis In botany , the cortex is the outer layer of the plant stem stem or root of a plant, bounded on the outside by the Epidermis botany epidermis and on the inside by the endodermis . It is composed mostly of undifferentiated cell s, usually large thin walled parenchyma cells of the ground tissue system. The outer cortical cells often acquire irregularly thickened cell walls, and are called collenchyma cells. Some of the outer cortical cells may contain chloroplast s. It is responsible for the transportation of materials into the central cylinder of the root through diffusion and may also be used for food storage in the form of starch. See also Bast biology botany stub DEFAULTSORT Cortex Botany Category Plant anatomy Category Plant physiology es C rtex bot nica ht K t ks pt C rtex bot nica sr sh Kora botanika ... more details
Onesource date March 2008 Taxobox name Cicadomorpha image CicadaClimbingBareTree.jpg image caption A Magicicada species cicada regnum Animal ia phylum Arthropod a classis Insect a ordo Hemiptera subordo Auchenorrhyncha infraordo Cicadomorpha subdivision ranks Superfamilies subdivision Cercopoidea br Cicadoidea br Membracoidea br Palaeontinoidea The Cicadomorpha is the infraorder of the Hemiptera which contains the cicada s, leafhopper s, treehopper s, and spittlebug s. There are approximately 35000 described species worldwide. Distributed worldwide, all members of this group are plant feeders, and many produce either audible sounds or substrate vibrations as a form of communication. Classification As mentioned under Auchenorrhyncha , some authors use the name Clypeorrhyncha as a replacement for the Cicadomorpha. Nymphs of many Cicadomorphans coat themselves with secretions from specialized Malpighian tubule system Malphigian tubules . They are never coated with hydrophobic wax as seen in the nymphs of Fulgoromorpha . Most Cicadomorphas have a filter chamber in their mid gut which helps remove excess water from the xylem or phloem sap that they feed on. ref C. H. Dietrich in Resh, V. H. & Carde, R. T. Eds. 2003 Encyclopedia of Insects. Academic Press. ref References reflist Category Auchenorrhyncha es Cicadomorpha fr Cicadomorpha it Cicadomorpha lt Cikadiniai nl Zingcicadeachtigen no Cicadomorpha ru Cicadomorpha ... more details
italic title Taxobox name Epinotia granitalis image image width 250px image caption regnum Animal ia phylum Arthropod a classis Insect a ordo Lepidoptera zoodivision Ditrysia zoosectio Cossina familia Tortricidae tribus genus Epinotia species E. granitalis binomial Epinotia granitalis binomial authority Butler, 1881 synonyms The Cypress Bark Moth Epinotia granitalis is a moth of the Tortricidae family. It is endemic to Japan . The wingspan is 13 16 mm. Adults are on wing from early June to late July. The larvae feed on Cryptomeria japonica and Chamaecyparis obtusa . The larvae bore into the bark and feed on the phloem of a standing tree. The cambium is injured, but since the damaged area is only small, the callus soon heals the damaged part and the tree continues to grow normally, but the scar and discolouration remain and increase annually. These scars lead to a degradation in the commercial value of the timber. External links http nlbif.eti.uva.nl bis tortricidae.php?selected beschrijving&menuentry soorten&id 188 Eurasian Tortricidae Category Tortricidae Olethreutinae stub vi Epinotia granitalis ... more details
Encyclopedia
top
