Phloem is the vascular tissue in charge of transport and distribution of the organic nutrients. The phloem is also a pathway to signaling molecules and has a structural function in the plant body. It is typically composed of three cell types: sieve elements, parenchyma, and sclerenchyma.

Xylem transports water and mineral salts from the roots up to other parts of the plant, while phloem transports sucrose and amino acids between the leaves and other parts of the plant.

At the sources (usually the leaves), sugar molecules are moved into the sieve elements (phloem cells) through active transport. This water creates turgor pressure in the sieve elements, which forces the sugars and fluids down the phloem tubes toward the sinks.

The phloem carries food downward from the leaves to the roots. Xylem cells constitute the major part of a mature woody stem or root. They are stacked end to end in the center of the plant, forming a vertical column that conducts water and minerals absorbed by the roots upward through the stem to the leaves.

In a mature flowering plant or tree, most of the cells that make up the xylem are specialised cells called vessels. Lose their end walls so the xylem forms a continuous, hollow tube. Become strengthened by a chemical called lignin . The cells are no longer alive.

Xylem and phloem are vascular tissues. They bring about the conduction of water, minerals and food to different plant parts. Xylem and phloem are made of different cell types, who come together to perform a common function, hence they are called complex tissues.

Xylem is different from the phloem as xylem conducts water from roots to leaves and phloem conducts food from leaves to different parts of plants.