Phloem conducts food materials from leaves to the other parts of the plant. It is made up of four types of cells.

1. Sieve elements

2. Companion cells

3. Phloem fibres

4. Phloem parenchyma

1. Sieve elements

Sieve elements are the conducting elements of the phloem. Sieve elements are of two types – sieve cells and sieve tubes.

Sieve cells are present in Pteridophytes and Gymnosperms whereas sieve tubes are present in Angiosperms.

2. Companion cells 

Companion cells are thin walled elongated specialized Parenchyma cells. They are associated with sieve elements. They have a prominent nucleus and cytoplasm. They help the sieve tube in conduction of food materials in angiosperms.

3. Phloem fibres 

The fibres of sclerenchyma associated with phloem are called phloem fibres. They are also called bast-fibres. They give mechanical support to the plant. Among the four types of phloem cells, phloem fibres are the only dead tissues.

4. Phloem parenchyma

The parenchyma cells associated with phloem are called phloem parenchyma. They store starch and fats.