Monocot Stem

 

Epidermis:

  • It is made up of a single layer of cells with an external coating of waxy cuticle.
  • Epidermal outgrowths are usually absent.
  • Very few stomata are found.

Hypodermis:

  • It is composed a few layer of sclerenchyma cells lying just below the epidermis.
  • It gives mechanical support to the stem.

Ground Tissue:

  • The ground tissue is not differentiated into cortex, epidermis pericycle or pith.
  • It is composed of a large mass of loosely arranged parenchyma cells found next to hypodermis.
  • The cell wall is composed of cellulose.
  • The cells contain reserve food materials.

Vascular tissue

  • The vascular bundles are embedded within the ground tissue.
  • Numerous bundles are found scattered throughout the ground tissue.
  • Smaller bundles are seen towards the periphery and are more crowded.
  • The larger ones are seen towards the centre and are more spaced.
  • Each vascular bundle is surrounded by a sclerenchymatous bundle sheath.
  • The bundles are collateral closed. It is a characteristic feature of monocot stem.
Dicot Stem Monocot Stem
Epidermis – Have outgrowths (trichomes) Epidermis – No outgrowths
Hypodermis – Made of collenchyma Hypodermis – Made of sclerenchyma
Ground tissue – Differentiated into cortex, endodermis, pericycle, medulllary rays and pith. Ground tissue – No Differentiation
Xylem & Phloem – Few in number Xylem & Phloem – Numerous
Vascular bundles – Arranged in the form of a brocken ring Vascular bundles – Scattered in the ground tissue
Cambium – Present between the xylem and phloem Cambium – Absent, hence closed type
Phloem parenchyma – Present Phloem parenchyma – Absent
Vascular bundles – Have a sclerenchymatous bundle cap Vascular bundles – Have a sclerenchymatous bundle sheath