Describe the vascular bundles of a dicot stem.

Explanation

Vascular bundles
1. The vascular bundles consist of xylem, phloem and cambium. Xylem and pholem in the stem occur together and form the vascular bundles.
2. Vascular bundles are wedge shaped.
3. They are arranged in the form of a ring.
Each vascular bundle is conjoint, collateral, open and endarch.
Phloem
1. Primary phloem lies towards the periphery.
2. it consists of protophloem and metaphloem.
3. Phloem consists of sieve tubes, companion cells and phloem parenchyma.
4. Phloem fibres are absent in the primary phloem
5. Phloem conducts organic food materials from the leaves to other parts of the plant body.
Combium
1. Combium consists of brick shaped and thin walled meristematic cells.
2. It is one to four layers in thickness.
3. These cells are capable of forming new cells during secondary growth.
Xylem
Xylem consists of xylem fibres, xylem parrencyma vessels and tracheids. Vessels are thick walled and arranged in a few rows.
Xylem conducts water and minerals from the root to the other parts of the plant body.