Why are xylem and phloem called complex tissues?
Xylem and phloem are made of different cell types, who come together to perform a common function, hence they are called complex tissues. The xylem is composed of vessels, tracheids, xylem fibres and xylem parenchyma. Phloem is composed of sieve tubes, companion cells, phloem fibres and phloem parenchyma.
