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Encyclopedia > Vascular tissue
Cross section of celery stalk, showing vascular bundles, which include both phloem and xylem.
This is an article about vascular tissue in plants. For transport in animals, see Circulatory system.

Vascular tissue is a complex tissue found in vascular plants, meaning that it is composed of more than one cell type. The primary components of vascular tissue are the xylem and phloem. These two tissues transport fluid and nutrients internally. There are also two meristems associated with vascular tissue: the vascular cambium and the cork cambium. All the vascular tissues within a particular plant together constitute the vascular tissue system of that plant. Image File history File links Download high resolution version (1600x1200, 168 KB) A cross section of celery File links The following pages link to this file: Celery User:Fir0002/Fir0002 gallery ... Image File history File links Download high resolution version (1600x1200, 168 KB) A cross section of celery File links The following pages link to this file: Celery User:Fir0002/Fir0002 gallery ... Binomial name L. Percentages are relative to US recommendations for adults. ... Diagram of the human circulatory system. ... Biological tissue is a group of cells that perform a similar function. ... Divisions Non-seed-bearing plants Equisetophyta Lycopodiophyta Psilotophyta Pteridophyta Superdivision Spermatophyta Pinophyta Cycadophyta Ginkgophyta Gnetophyta Magnoliophyta The vascular plants are plants in the Kingdom Plantae (also called Viridiplantae) that have specialized tissues for conducting water. ... In vascular plants, xylem is one of the two types of transport tissue in plants, phloem being the other one. ... In vascular plants, phloem is the living tissue that carries organic nutrients, particularly sucrose, a sugar, to all parts of the plant where needed. ... A meristem is a tissue in plants consisting of undifferentiated cells (meristematic cells) and found in zones of the plant where growth can take place. ... The vascular cambium is a lateral meristem: The vascular cambium is the source of both the secondary xylem (inwards) and the secondary phloem (outwards), and hence is located between these tissues in the stem. ... Cork cambium is a tissue found in woody plants as part of the periderm. ...


The cells in differentiated vascular tissue are typically long and slender. Since the xylem and phloem function in the conduction of water, minerals, and nutrients throughout the plant, it is not surprising that their form should be similar to pipes. The individual cells of phloem are connected end-to-end, just as the sections of a pipe might be. As the plant grows, new vascular tissue differentiates in the growing tips of the plant. The new tissue is aligned with existing vascular tissue, maintaining its connection throughout the plant. The vascular tissue in plants is arranged in long, discrete strands called vascular bundles. These bundles include both xylem and phloem, as well as supporting and protective cells. In stems and roots, 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 dicots, there may be phloem located inwardly from the xylem as well. Embryonic stem cells differentiate into cells in various body organs. ... Stem showing internode and nodes plus leaf petiole and new stem rising from node. ... Primary and secondary roots in a cotton plant In vascular plants, the root is that organ of a plant body that typically lies below the surface of the soil (compare with stem). ... Orders see text Dicotyledons or dicots are flowering plants whose seed contains two embryonic leaves or cotyledons. ...


Between the xylem and phloem is a meristem called the vascular cambium. This tissue divides off cells that will be become additional xylem and phloem. This growth increases the girth of the plant, rather than its length. As long as the vascular cambium continues to produce new cells, the plant will continue to grow more stout. In trees and other plants that develop wood, the vascular cambium allows the expansion of vascular tissue that produces woody growth. Because this growth ruptures the epidermis of the stem, woody plants also have a cork cambium that develops among the phloem. The cork cambium gives rise to thickened cork cells to protect the surface of the plant and reduce water loss. Both the production of wood and the production of cork are forms of secondary growth. A meristem is a tissue in plants consisting of undifferentiated cells (meristematic cells) and found in zones of the plant where growth can take place. ... The vascular cambium is a lateral meristem: The vascular cambium is the source of both the secondary xylem (inwards) and the secondary phloem (outwards), and hence is located between these tissues in the stem. ... Drawing of the structure of cork as it appeared under the microscope to Robert Hooke from Micrographia which is the origin of the word cell. Cells in culture, stained for keratin (red) and DNA (green). ... The coniferous Coast Redwood, the tallest tree species on earth. ... Trunks A tree trunk as found at the Veluwe, The Netherlands Wood is a solid material derived from woody plants, notably trees but also shrubs. ... The epidermis is the outer multi-layered group of cells covering the leaf and young tissues of a plant. ... Cork cambium is a tissue found in woody plants as part of the periderm. ... Cork is a tissue found in some plants, which consists tightly packed dead cells. ... In vascular plants, secondary growth or, perhaps more accurately, secondary thickening is the result of the activity of the vascular cambium. ...


In leaves, the vascular bundles are located among the spongy mesophyll. The xylem is oriented toward the adaxial surface of the leaf (usually the upper side), and phloem is oriented toward the abaxial surface of the leaf. This is why aphids are typically found on the underside of the leaves rather than on the top, since the phloem transports sugars manufactured by the plant and they are closer to the lower surface. “Foliage” redirects here. ... Families There are 10 families: Adelgidae - adelgids, conifer aphids, Adelges cooleyi, Hemlock Wolly Adelgid, Adelges piceae Anoeciidae Aphididae Drepanosiphidae Homomasagymibutae Greenideidae Hormaphididae Lachnidae Mindaridae Pemphigidae Phloeomyzidae Phylloxeridae Thelaxidae Aphids, also known as greenfly, blackfly or plant lice, are minute plant-feeding insects in the superfamily Aphidoidea in the homopterous division...


See also


  Results from FactBites:
 
Vascular tissue - Wikipedia, the free encyclopedia (486 words)
Vascular tissue is a complex tissue found in vascular plants.
The primary components of vascular tissue are the xylem and phloem.
The xylem is oriented toward the adaxial surface of the leaf (usually the upper side), and phloem is oriented toward the abaxial surface of the leaf.
Vascular bundles (477 words)
Vascular tissue is made up of different types of plant cells which transport water and organic and inorganic molecules from where they are manufactured or absorbed in the plant, to where they used or stored.
The two main transport tissues in a vascular bundle are phloem and xylem and between these is a very important layer of cells, the cambium, which is able to divide.
The xylem of the vascular bundles is orientated towards the middle of the stem and the phloem towards the outside.
  More results at FactBites »

 
 

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