Name two types of meristematic tissues and state their respective roles in plant growth.

Two types of meristematic tissues are: 
1. Apical Meristem: Located at the tips of roots and shoots. Its role is to increase the length of the plant (primary growth). 
2. Lateral Meristem (e.g., vascular cambium, cork cambium): Located along the sides of stems and roots. Its role is to increase the girth or diameter of the plant (secondary growth).