The vascular bundle

• The vascular bundle in the roots:

  • Xylem and phloem are components of the vascular bundle, which serves to enable transport of substances as well as for structural support.

  • The xylem vessels are arranged in an X shape in the centre of the vascular bundle.

  • This enables the plant to withstand various mechanical forces such as pulling.

  • The X shape arrangement of xylem vessels is surrounded by endodermis, which is an outer layer of cells which supply xylem vessels with water.

  • An inner layer of meristem cells known as the pericycle
• The vascular bundle in the stem:

  • Xylem is located on the inside in non-wooded plants to provide support and flexibility to the stem

  • Phloem is found on the outside of the vascular bundle

  • There is a layer of cambium in between xylem and phloem, that is meristem cells which are involved in production of new xylem and phloem tissue
• The vascular bundle in the leaf:

  • The vascular bundles form the midrib and veins of a leaf

  • Dicotyledonous leaves have a network of veins, starting at the midrib and spreading outwards which are involved in transport and support