Where is Phloem tissue found?

Option B

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. Primary phloem is formed by the apical meristems (zones of new cell production) of root and shoot tips; it may be either protophloem, the cells of which are matured before elongation (during growth) of the area in which it lies, or metaphloem, the cells of which mature after elongation.

Sieve tubes, which are columns of sieve-tube cells having perforated, sievelike areas in their lateral or end walls, provide the channels in which food substances travel. Phloem parenchyma cells, called transfer cells and border parenchyma cells, are located near the finest branches and terminations of sieve tubes in leaf veinlets, where they also function in the transport of foods. Phloem fibres are flexible long cells that make up the soft fibres (e.g., flax and hemp) of commerce.