What are lateral and intercalary meristem?

Lateral meristem is the secondary meristematic tissue that arises from permanent tissues and is responsible for increasing the thickness of the plant. It is located on the lateral side of stems and roots.

The cork cambium and vascular cambium are two types of Lateral meristem.

In some plants,  Intercalary meristem is present between the region of permanent or mature tissue and is responsible for the growth in length of the middle area. These meristematic tissues are capable of cell division and thus allows rapid growth and regrowth of few monocots.

It is located in the internodal region or at the area between the leaves attachment.