Phloem is a living tissue in vascular plants which conducts the soluble organic compounds synthesized during photosynthesis downwards from the leaves.
Listed below are the constituents of phloem:
- Companion cells – it appears to check the activity of the adjacent sieve element and participates in loading and unloading of the sugar into the sieve element
- Sieve tubes – these elongated living cells, conveys carbohydrates, chiefly sucrose from leaves to roots and fruits
- Phloem fibres – they are commercially useful as they possess great pliability and tensile strength
- Phloem parenchyma – also known as transfer cells, they are found near the finest branches, ends of sieve tubes in leaf veinlets, functional here in conveying food