Ground Tissue - Collenchyma

Collenchyma

The word 'collenchyma' is derived from the Greek word κολλα ("kól-la"), meaning "glue", which refers to the thick, glistening appearance of the walls in fresh tissues. Collenchyma tissue is composed of elongated cells with irregularly thickened walls. They provide structural support, particularly in growing shoots and leaves. Collenchyma tissue composes, for example, the resilient strands in stalks of celery. Its growth is strongly affected by mechanical stress upon the plant. The walls of collenchyma in shaken plants (to mimic the effects of wind etc.), may be 40%-100% thicker than those not shaken. The wall is made up of cellulose and pectin.

There are three principal types of collenchyma:

• Angular collenchyma (thickened at intercellular contact points)
• Tangential collenchyma (cells arranged into ordered rows and thickened at the tangential face of the cell wall)
• Lacunar collenchyma (have intercellular space and thickening proximal to the intercellular space)

Collenchyma cells are most often found adjacent to outer growing tissues, the vascular cambium and are known for increasing structural support and integrity.