16. What is a limiting factor?

Definition of limiting factor.

1 : the factor that limits the reaction rate in any physiological process governed by many variables.

2 : the environmental factor that is of predominant importance in restricting the size of a population lack of winter browse is a limiting factor for many deer herds.

* They have xylem and phloem.

* They have true roots.

* They grow near water.

Explanation:

Since horsetails are vascular they have vascular tissue (xylem & phloem) and true roots, stems, and leaves.  They grow in marshy areas in or near water and can be several feet in height.