QS Study

Formation of cambium ring:

Cambium is a meristem that increases the girth of stems and roots by producing additional xylem and phloem. The intrafascicular and interfascicular cambia form a ring which separates the primary xylem and primary phloem, and is known as cambium ring.

It is the first step of secondary growth.

(i) At the beginning of secondary growth, few parenchyma cells lying between two adjacent patches of fascicular cambium of vascular bundles become meristematic and produce inter fascicular cambium

(ii) The inter fascicular cambium joins the fascicular cambium on both sides and forms a complete cambium ring.

(iii) Cambium ring is the lateral meristem.

Fig: cambium ring.


The functions are to produce;


  • Intrafascicular Cambium: It is primary in origin, present in between primary phloem and primary xylem.
  • Fascicular Cambium: It is true secondary meristem. It originates from parenchyma cells of modularly rays region. It lies in between the vascular bundles.
  • Vascular Cambium Ring: Both intrafascicular and Fascicular cambium joins together and forms cambium ring.