Internal structure of monocot stem

Internal structure of monocot stem

monocot stem consist of following internal structure:

Epidermis
it is the outermost layer of compactly arranged parenchymatous cells.the cells are elongated and rectangular or barrel shaped.it is externally covered by thin layer of cuticle.sometimes stomata are also found in epidermis but epidermal hair is absent.

Hypodermis
epidermis is followed by a few layer of hypodermis.it consist of compactly arranged sclerenchymatous cells without internal cellular space.they provide mechanical support.

Ground tissue
the region between hypodermis and centre of stem is called ground tissue.it consist of thin walled parenchymatous cells with wall to wall contact i.e no intercellular space.

Vascular bundles

the vascular bundles are conjoint,cillateral and closed type.it consists of xylem towards the centre and phloem towards the peripheri.cambium is absent.the vascular bundles are found scattered irregularly throughout the ground tissue.the smaller and closedly packed vascular bundle lies toward outerside and larger toward centreeach vascular bundle is surrounded by sclerenchymatous bundle sheath.

Xylem:xylem are usually y-shaped.the metaxylem vessels are wider with pitted thickenings ehereas protoxylem vessels are narrower with spiral thickening.a large lusigenous cavity is found below protoplasm.it stores water.xylem shows endarch condition.

Phloem:
it lies on the outer side of the xylem in vascular bundles.phloem lacks phloem parenchyma.phloem is diffrentiated into proto and meta phloem.