Vascular cambium

Vascular Cambium

Cross-section of a sunflower stem showing the vascular cambium

The vascular cambium is a type of plant tissue located between the xylem and phloem in the stems and roots of vascular plants. It is a lateral meristem and is responsible for the secondary growth of stems and roots, which results in an increase in thickness.

Structure

The vascular cambium is a thin layer of cells that forms a continuous ring in the stem and root. It consists of two types of cells: fusiform initials and ray initials. The fusiform initials are elongated cells that divide to produce new xylem and phloem cells, while the ray initials are smaller and produce radial files of cells that form the vascular rays.

Function

The primary function of the vascular cambium is to produce secondary xylem (wood) and secondary phloem. As the cambium divides, it adds layers of xylem to the inside and phloem to the outside. This process increases the diameter of the stem or root and contributes to the plant's ability to transport water, nutrients, and photosynthates.

Development

The vascular cambium develops from the procambium, a primary meristematic tissue, during the transition from primary to secondary growth. In dicotyledons, the cambium forms a complete ring, while in monocotyledons, it is often absent or less developed.

Importance

The activity of the vascular cambium is crucial for the formation of wood and bark, which are important for the structural support and protection of the plant. It also plays a role in the plant's ability to heal wounds and regenerate tissues.

Related Pages

• Xylem
• Phloem
• Meristem
• Secondary growth

References

• Evert, R. F. (2006). Esau's Plant Anatomy: Meristems, Cells, and Tissues of the Plant Body: Their Structure, Function, and Development. John Wiley & Sons.
• Mauseth, J. D. (2008). Botany: An Introduction to Plant Biology. Jones & Bartlett Learning.