phloem, also called bast, tissues in plants that conduct foods made in the leaves to all other parts of the plant. Phloem is composed of various specialized cells called sieve tubes, companion cells, phloem fibres, and phloem parenchyma cells. ... The other cell types in the phloem may be converted to fibres.
What are the types of phloem?
Types of phloem - definition
- Sieve tubes: Transport sugars and nutrients up and down the plants in sieve cells.
- Companion cells: Controls the activity of sieve tube.
- Phloem parenchyma: Provides mechanical strength to the plant.
- Phloem fibres: Stores compound such as starch.
What are the phloem and xylem called?
One xylem and one phloem are known as a 'vascular bundle' and most plants have multiple vascular bundles running the length of their leaves, stems, and roots. Xylem tissue is used mostly for transporting water from roots to stems and leaves but also transports other dissolved compounds.
