Why are xylem and phloem called complex tissues?


HARITHA,Subject Matter Expert at Edumarz

Solution:The complex tissues are formed of more than one type of cell and these cells function together as a unit.Xylem and phloem are the complex tissues present in plants.They constitute the complex tissues in plants.


  • The main function of xylem tissue is conducting tissue for water and minerals from roots to the stem and leaves and it also provides mechanical strength to different plant parts

  • It is formed of four types of elements: tracheids, vessels, xylem fibres, and xylem parenchyma.Tracheids are elongated or tube-like cells with thick and lignified walls and tapering ends.They also lack protoplasm.

  • Vessels are long cylindrical tube-like structures formed of many cells called vessel members

  • Xylem fibres are characterised by  highly thickened walls

  • Xylem parenchyma cells are living,thin-walled cells and their cell walls are composed of cellulose

  • The primary xylem is present in two forms called protoxylem and metaxylem


  • The main function of phloem tissue is the transport of food materials  mainly from leaves to other parts of the plant

  • In angiosperms, phloem is formed of sieve tube elements,companion cells, and phloem parenchyma

  • Gymnosperms contain albuminous cells and sieve cells but they lack sieve tubes and companion cells.

Leave a Reply