Vascular bundle: Difference between revisions

Latest revision as of 03:53, 29 March 2025

A vascular bundle is a part of the transport system in vascular plants. It consists of xylem, phloem, and cambium tissues. These bundles are responsible for the conduction of water, nutrients, and food throughout the plant.

File:Metasequoia glyptostroboides leaf vascular bundle.jpg

Vascular bundle in Metasequoia leaf

File:Pine Leaf Vascular Bundle.jpg

Vascular bundle in pine leaf

Structure[edit]

Vascular bundles are typically arranged in a ring in dicotyledons and scattered in monocotyledons. Each bundle contains xylem, which transports water and minerals from the roots to the rest of the plant, and phloem, which distributes the sugars produced by photosynthesis in the leaves.

Xylem[edit]

The xylem is located towards the center of the vascular bundle. It is composed of tracheids, vessels, and xylem parenchyma. These elements work together to facilitate the upward movement of water and dissolved minerals.

Phloem[edit]

The phloem is situated towards the outside of the vascular bundle. It consists of sieve tubes, companion cells, phloem fibers, and phloem parenchyma. The primary function of the phloem is to transport organic nutrients, particularly sucrose, from the leaves to other parts of the plant.

Cambium[edit]

In dicotyledons, a layer of cambium is present between the xylem and phloem. This cambium is a type of meristematic tissue that contributes to the secondary growth of the plant, increasing the thickness of stems and roots.

Types of Vascular Bundles[edit]

Vascular bundles can be classified based on their arrangement and structure:

Collateral - Xylem and phloem are arranged side by side on the same radius.
Bicollateral - Phloem is present on both sides of the xylem.
Concentric - One type of tissue surrounds the other, either xylem surrounding phloem (amphicribral) or phloem surrounding xylem (amphivasal).

Function[edit]

The primary function of vascular bundles is the transport of water, nutrients, and food throughout the plant. They also provide structural support, helping the plant maintain its shape and resist external forces.

Related Pages[edit]

@@ Line 1: / Line 1: @@
-'''Vascular bundle''' is a part of the transport system in vascular plants. The transport itself happens in [[vascular tissue]], which also provides support and structure to the plant. Vascular bundles consist of [[xylem]] and [[phloem]] tissues, which are responsible for carrying water, minerals, and the products of photosynthesis throughout the plant.
+A '''vascular bundle''' is a part of the transport system in [[vascular plants]]. It consists of [[xylem]], [[phloem]], and [[cambium]] tissues. These bundles are responsible for the conduction of water, nutrients, and food throughout the plant.
+[[File:Leitbündel.svg|Vascular bundle diagram|thumb]]
+[[File:Celery_cross_section.jpg|thumb|Cross section of celery showing vascular bundles|left]]
+[[File:Leitbuendel_zea_mays.jpg|thumb|Vascular bundle in maize]]
+[[File:Metasequoia_glyptostroboides_leaf_vascular_bundle.jpg|thumb|Vascular bundle in Metasequoia leaf|left]]
+[[File:Pine_Leaf_Vascular_Bundle.jpg|thumb|Vascular bundle in pine leaf]]
+== Structure ==
-== Structure ==
+Vascular bundles are typically arranged in a ring in [[dicotyledons]] and scattered in [[monocotyledons]]. Each bundle contains xylem, which transports water and minerals from the roots to the rest of the plant, and phloem, which distributes the sugars produced by [[photosynthesis]] in the leaves.
+=== Xylem ===
-Vascular bundles are found throughout the plant. They are part of the [[root]], [[stem]], and [[leaf]] structures. In stems and roots, the xylem and phloem are often arranged in a ring. In leaves, they form the [[vein]]s that can be seen when looking at a leaf.
+The xylem is located towards the center of the vascular bundle. It is composed of tracheids, vessels, and xylem parenchyma. These elements work together to facilitate the upward movement of water and dissolved minerals.
-The xylem tissue is typically located towards the interior of the vascular bundle, while the phloem is located towards the exterior. This arrangement is known as a collateral bundle. In some plants, additional xylem and phloem tissues are located in the center of the bundle, forming a bicollateral bundle.
+=== Phloem ===
-== Function ==
+The phloem is situated towards the outside of the vascular bundle. It consists of sieve tubes, companion cells, phloem fibers, and phloem parenchyma. The primary function of the phloem is to transport organic nutrients, particularly sucrose, from the leaves to other parts of the plant.
-The primary function of the vascular bundle is to transport water, minerals, and sugars throughout the plant. The xylem carries water and minerals from the roots to the rest of the plant, while the phloem carries sugars, the products of photosynthesis, from the leaves to the rest of the plant.
+=== Cambium ===
-Vascular bundles also provide structural support to the plant. The xylem tissue, in particular, is strong and rigid, helping to support the plant and keep it upright.
+In dicotyledons, a layer of cambium is present between the xylem and phloem. This cambium is a type of meristematic tissue that contributes to the secondary growth of the plant, increasing the thickness of stems and roots.
 == Types of Vascular Bundles ==
-There are three main types of vascular bundles: collateral, bicollateral, and concentric.
+Vascular bundles can be classified based on their arrangement and structure:
-* '''Collateral''' bundles have the xylem located towards the inside and the phloem towards the outside. They are the most common type of vascular bundle.
+* '''Collateral''' - Xylem and phloem are arranged side by side on the same radius.
-* '''Bicollateral''' bundles have an additional layer of phloem located inside the xylem. They are less common than collateral bundles and are typically found in certain types of dicotyledonous plants.
+* '''Bicollateral''' - Phloem is present on both sides of the xylem.
-* '''Concentric''' bundles have either the xylem or the phloem completely surrounding the other. They are typically found in monocotyledonous plants.
+* '''Concentric''' - One type of tissue surrounds the other, either xylem surrounding phloem (amphicribral) or phloem surrounding xylem (amphivasal).
-== See Also ==
+== Function ==
+The primary function of vascular bundles is the transport of water, nutrients, and food throughout the plant. They also provide structural support, helping the plant maintain its shape and resist external forces.
+== Related Pages ==
-* [[Plant anatomy]]
-* [[Vascular tissue]]
 * [[Xylem]]
 * [[Phloem]]
+* [[Cambium]]
+* [[Vascular plant]]
 [[Category:Plant anatomy]]
-[[Category:Botany]]
-[[Category:Plant physiology]]
-{{stub}}