Describe the vascular bundles of monocot stem.

Explanation

Vascular bundles:Vascular bundles are scattered (atactostele)in the parenchyma ground tissue.Each vascular bundle is surrounded by a sheath of sclerenchymatous fibres called bundle sheath.The vascular bundles are conjoint,collateral,endarch and closed.Vascular bundles are numerous,small and closely arranged in the peripheral portion.Towards the centre,the bundles are comparatively large in size and loosely arranged.Vascular bundles are skull or oval shaped.
Phloem:The phloem in the monocot stem consists of sieve tubes and campanion cells.Phloem parenchyma and phloem fibres are absent. It can be distinguished intoan outer crushed protophloem and an inner metaphloem.
Xylem:Xylem vessels are arranged in the form of .Y. the two metaxylem vessels at the base.In a mature bundle,the lowest protoxylem disintegrates and forms a cavity known as protoxylem lacuna.