The cambium in a dicot stem is located between the xylem and phloem in the vascular bundles. Specifically, there are two types of cambium: intrafascicular cambium (within the vascular bundles) and interfascicular cambium (between the vascular bundles).
Types of Cambium in Dicot Stems
Dicot stems exhibit two types of cambium, contributing to secondary growth:
- Intrafascicular Cambium: This is the primary meristem that originates from the procambium within the vascular bundles. It is situated directly between the primary xylem and primary phloem.
- Interfascicular Cambium: This secondary meristem develops from parenchyma cells located in the medullary rays between adjacent vascular bundles. It connects the intrafascicular cambium rings, forming a complete cambial ring.
Formation of the Cambial Ring
The cambial ring, responsible for secondary growth, is formed through the combined activity of:
- Intrafascicular cambium present within the vascular bundles.
- Interfascicular cambium that develops between the vascular bundles.
These two cambial types merge to form a continuous ring. This ring then divides to produce secondary xylem (wood) on the inside and secondary phloem on the outside, resulting in increased stem girth.
Role in Secondary Growth
The cambium's primary function is to facilitate secondary growth, which leads to an increase in the stem's diameter. It creates new vascular tissues that help support the increasing size of the plant. The cambium is crucial for the plant's long-term survival as it allows it to grow taller and wider, competing more effectively for resources.
