In higher plants, the phase lies behind the region of elongation is:

Explanation

In higher plants, the phase lies behind the region of elongation is maturation phase.The "maturation phase" refers to a stage or period in the development and growth of an organism or system when it reaches a state of maturity or completeness. In biology, the maturation phase can describe the final stage of an organism's development when it has reached its full adult form and functionality. For example, in the maturation phase of a butterfly's life cycle, it transitions from a pupa to an adult butterfly.The specific meaning of the "maturation phase" can vary depending on the field or context in which it is used. However, it generally signifies a stage of development in which an organism, system, or process reaches a state of full development, readiness, or maturity.