Wood is primarily composed of xylem cells with cell walls made of cellulose and lignin.

Streptococcal bacteria have been found living inside the walls of water-conducting xylem cells in spent reeds.

The innermost area of the root contains vascular tissue, which is made up of xylem cells and phloem cells.

The movement in phloem is bidirectional, whereas, in xylem cells, it is unidirectional (upward).

The movement in phloem is multi-directional, whereas, in xylem cells, it is one-directional (upwards).

Since xylem cells comprise dead, lignified tissue, subsequent rings of xylem are added to those already present, forming wood.

Some xylem cells carry water and nutrients up from the roots, while others store food.

Wood consists of xylem cells, and bark is made of phloem and other tissues external to the vascular cambium.

Vessel members are hollow xylem cells without end walls that are aligned end-to-end so as to form long continuous tubes.

The most distinctive xylem cells are the long tracheary elements that transport water.