Secondary growth occurs in most dicot stems, with secondary vascular tissues and periderm increasing the thickness or girth of the stem.
Due to the action of the vascular cambium, normal secondary growth in the dicot stem increases the diameter of the plant stem.
The vascular bundles in dicot stems are organised in a ring and are conjoint, collateral, and open (cambium is present).
Fascicular or Intrafascicular cambium is the cambium found between the xylem and phloem in vascular bundles.
Some cells of the Medullary rays that are present between vascular bundles become meristematic during secondary growth, and this is known as Interfascicular cambium.
The Cambium ring is made up of both intrafascicular and interfascicular cambium, which together form a full ring.
Secondary growth is triggered by the cambium ring.
