Non-living cell of phloem is Phloem sclerenchyma.

Introduction:
Phloem is a complex tissue in plants responsible for the transport of organic nutrients, such as sugars, from the leaves to other parts of the plant. It consists of several types of cells, including living cells like sieve tubes and companion cells, as well as non-living cells like phloem fibers and phloem sclerenchyma.

Phloem Sclerenchyma:
Phloem sclerenchyma is a type of non-living cell found in the phloem tissue of plants. It is derived from the sclerenchyma tissue, which provides mechanical support to the plant. Phloem sclerenchyma cells are thick-walled and dead at maturity. They are highly lignified, making them rigid and strong. These cells are elongated and have tapering ends.

Function of Phloem Sclerenchyma:
Phloem sclerenchyma cells play a crucial role in providing mechanical support and protection to the phloem tissue. They strengthen the phloem tissue, preventing it from collapsing under pressure or damage. The thick lignified walls of these cells make them resistant to bending and compression.

Location:
Phloem sclerenchyma cells are typically found on the outer side of the phloem tissue, forming a protective layer around the living cells like sieve tubes and companion cells. They are present in the stems, roots, and leaves of plants.

Differences from Other Phloem Cells:
1. Phloem parenchyma: Unlike phloem sclerenchyma, phloem parenchyma cells are living cells that function in storage and metabolism. They have thin cell walls and are involved in the lateral transport of sugars and other organic compounds.
2. Sieve tubes: Sieve tubes are also living cells responsible for the translocation of sugars in the phloem. They are elongated cells with perforated end walls called sieve plates. The sieve tubes are associated with companion cells, which provide metabolic support to the sieve tubes.
3. Companion cells: Companion cells are living cells closely associated with sieve tubes. They provide energy and nutrients to the sieve tubes and help in the loading and unloading of sugars.

Conclusion:
Phloem sclerenchyma is a non-living cell found in the phloem tissue of plants. It provides mechanical support and protection to the phloem tissue. Unlike other phloem cells like phloem parenchyma, sieve tubes, and companion cells, phloem sclerenchyma cells are dead at maturity and have thick lignified walls.