Parenchyma is generally present in all organs of the plant. It forms the ground tissue in a plant. Parenchyma is a living tissue and made up of thin walled cells. The cell wall is made up of cellulose. Parenchyma cells may be oval, polyhedral, cylindrical, irregular, elongated or armed. Parenchyma tissue normally has prominent intercellular spaces. Parenchyma may store various types of materials like, water, air, ergastic substances. It is usually colourless. The turgid parenchyma cells help in giving rigidity to the plant body. Partial conduction of water is also maintained through parenchymatous cells. Occsionaliy Parenchyma cells which store resin, tannins, crystals of calcium carbonate, calcium oxalate are called idioblasts. Parenchyma is of different types and some of them are discussed as follows.
Types of paranchyma:
(i) Aerenchyma: Parenchyma which contains air in its intercellular spaces. It helps in aeration and buoyancy.
eg: Nymphae and Hydrilia.
(ii) Storage Parenchyma: parenchyma stores food materials.
eg: Root and stem tubers.
(iii) Stellate Parenchyma: Star shaped parenchyma.
eg: Petioles of Banana and Canna.
(iv) Chlorenchyma: Parenchyma cells with chlorophyll. Function is photosynthesis,
eg: Mesophyll of leaves.
(v) Prosenchyma: parenchyma cells became elongated, pointed and slightly thick walled. It provides mechanical support.
