How does xylem support lower vascular plants as well as transport water?

In lower vascular plants, xylem serves the dual purpose of water transport and structural support.

Water Transport

Xylem functions as a specialized vascular tissue responsible for conveying water and dissolved minerals from the roots to the rest of the plant. In these plants, the xylem is composed primarily of tracheids—elongated, hollow, nonliving cells. Water moves between these cells through pit membranes, which allow for the passage of water while preventing the spread of damaging air bubbles.123

Structural Support

The ability of xylem to provide physical support is largely due to the presence of lignin, a complex organic polymer that reinforces the cellulose cell walls. Lignin provides stiffness and compressive strength, which helps the plant withstand the force of gravity. Additionally, lignin waterproofs the cell walls, which further facilitates the efficient upward transport of water. While some larger species, such as tree ferns, derive support from surrounding tissues or root mantles, the lignified xylem remains a fundamental component of the plant's internal structural integrity.342