MONOCOT STEM:

a. Epidermis is uniseriate with compactly arranged barrel shaped cells covered with thick cuticle trichomes are absent.
b. Hypodermis: It is made up of a few layers of compactly arranged sclerenchyma cells. It provides mechanical support.
c. Ground tissue is the major component and is formed by an undifferentiated mass of loosely arranged parenchyma cells enclosing intercellular spaces. It is not differentiated into cortex or pith.
d. Many vascular bundles are found scattered in the ground tissue and this condition is called attactostele. From periphery to center there is a gradual decrease in the number of vascular bundles and increase in size. The vascular bundles are conjoint, collateral and closed with endarch xylem. Water filled lysigenous cavity present in association with the protoxylem. It is formed by the breakdown of inner protoxylem during earlier stages of growth. Phloem parenchyma is absent. The protophloem forms a thin layer above the functional metaphloem present towards the metaxylem. Each vascular bundle has a prominent bundle sheath made up of sclerenchyma fibres.