Collenchyma is a simple permanent tissue formed of elongated cells with thick primary or non-lignified walls. They are parenchyma like cells; uneven thickened walls are the characteristic feature of collenchyma cells. This wall thickening is primary in nature which is composed of cellulose, hemicellulose and pectin compounds. Simple pits are found in the thick and thin region of the cell wall. It is living tissues which possess vacuolated protoplasm. It is a mechanical tissue with elasticity and support to growing organs.
