Why are xylem and phloem called complex tissues?

When a plant tissue is made up of only one type of cell and they all do the same work, such a tissue is called as simple tissue. When a plant tissue is made up of many kinds of cells, all working in coordination for a common main function we call the tissue as complex tissue. read more

Xylem and phloem are known as complex tissues as they are made up of more than one type of cells. These cells work in a coordinated manner, as a unit, to perform the various functions of the xylem and phloem. Xylem helps in conducting water and minerals. It also provides mechanical support to plants. read more

So, coming to the point, xylem and phloem are called complex tissues because they are made up of different types of cells, while simple tissues are made up of same type of cells. xylem is made up of xylem parenchyma, tracheids, vessels and xylem fibre. read more