Phloem is a type of vascular tissue in plants that transports the products of photosynthesis, such as sugars, from the leaves to other parts of the plant. Phloem consists of several kinds of cells, such as sieve elements, companion cells, phloem parenchyma, and phloem fibres. Sieve elements are the main conducting cells that have pores in their walls to allow the flow of substances. Companion cells are specialized parenchyma cells that assist the metabolic functions of sieve elements. Phloem parenchyma are unspecialized parenchyma cells that store food and help in translocation. Phloem fibres are sclerenchyma cells that provide mechanical support to the phloem tissue.