Vascular cambium

Vascular Cambium

The vascular cambium is a type of meristematic tissue in plants that is responsible for the secondary growth of stems and roots. It is a lateral meristem and is crucial for the production of secondary xylem (wood) and secondary phloem. This growth increases the girth of the plant, allowing it to become thicker and stronger.

Cross-section of a Helianthus stem showing the vascular cambium.

Structure

The vascular cambium is a continuous ring of meristematic cells located between the primary xylem and primary phloem. It consists of two types of cells: the fusiform initials and the ray initials. The fusiform initials are elongated cells that divide to produce the secondary xylem and phloem, while the ray initials are smaller and produce the vascular rays, which are involved in the radial transport of nutrients and water.

Function

The primary function of the vascular cambium is to produce secondary vascular tissues. As the plant grows, the cambium divides to form new layers of xylem on the inside and phloem on the outside. This process is essential for the plant's ability to transport water, nutrients, and photosynthates throughout its structure. The secondary xylem forms the bulk of the plant's wood, providing structural support, while the secondary phloem is involved in the transport of organic nutrients.

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. The activity of the cambium is influenced by environmental factors such as light, temperature, and water availability.

Significance

The vascular cambium is vital for the plant's ability to grow in diameter and support larger structures. It allows trees and shrubs to develop thick trunks and branches, which are necessary for supporting leaves and reproductive structures. The wood produced by the cambium is also an important resource for humans, used in construction, paper production, and as a fuel source.

Related pages

• Xylem
• Phloem
• Meristem
• Secondary growth
• Plant anatomy