Xylem and Phloem are called complex tissues because they are composed of more than one cell type and they perform many functions necessary for the plant.

They are different form each other in following aspect-

● Xylem has 4 types of cells- tracheids, vessel elements, xylem fibers and xylem parenchyma. Tracheids, vessel elements and xylem fibers are dead cells of the xylem. The only living cells of xylem are parenchyma cells. Either tracheids or vessel elements are found in one xylem tissue.

● Phloem is also made of 4 types of cells namely- sieve tubes, phloem parenchyma, companion cells and phloem fibers. All the cells of the phloem are living except the phloem fibers. They are the dead cells in phloem.