noun, plural: cholenchymas
(botany) A fundamental type of tissue in plants characterized by cells with thicker primary wall than those of parenchyma
In plants, the collenchyma is one of the three fundamental types of tissues. The other two are the parenchyma and the sclerenchyma. The cells that make up the collenchyma are distinguished from the other two in having a thicker primary wall than that of the parenchyma. Both the collenchyma and the parenchyma cells have only a primary cell wall. The sclerenchyma cells have a secondary cell wall deposited between the primary cell wall and the plasma membrane. Nevertheless, both the collenchyma and the sclerenchyma are plant tissues providing structural support. The sclerenchyma though provides more strength and structural support to a plant.
The collenchyma cells are typically elongated. They typically occur in the growing shoots and leaves. An example of collenchyma tissue is the strands in the celery stalks. The collenchyma cells are often alive at maturity as opposed to sclerenchyma cells, which lose their protoplast at maturity.
Many of the collenchyma cells have irregular cell wall thickenings. When the primary cell wall is thickened at intercellular contact points, they are referred to as angular collenchyma. Collenchyma cells that have uniformly thickened cell walls are called annular collenchyma.
Word origin: from Greek kolla (“glue”)+énkhuma( “infusion”)