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1. Collenchyma
Dr. Jaydeep J. Sharma
Department of Botany
The Maharaja Sayajirao University of Baroda

2. Introduction
Collenchyma: a
living tissue providing
mechanical support
& elasticity.
Lies beneath the
epidermis in young
stems and petioles.
Extra deposition of
pectin on cell wall.

3. Definition
Greek: Colla = glue, enchyma
= infusion.
Definition: Collenchyma is a
living mechanical tissue with
unevenly thickened primary
cell walls, providing support
to growing plant organs.

4. General
Characteristics
Made of elongated living cells.
Cell wall thickened at corners with
cellulose, hemicellulose & pectin.
Usually without lignin (unlike
sclerenchyma).
Cells tightly packed, no intercellular
spaces.
Found in dicot stems, petioles,
leaves; absent in monocots.

5. Structure of
Collenchyma Cells
• Elongated polygonal cells.
• Thickening at corners only.
• Central vacuole, nucleus,
cytoplasm present.

6. Types of
Collenchyma
(Based on Wall
Thickening)
• Thickening at cell corners.
• Most common type.
Angular Collenchyma
• Thickening on tangential walls.
• Found in stems of Helianthus.
Lamellar Collenchyma
• Thickening around intercellular spaces.
• Found in Cucurbita.
Lacunar Collenchyma
• Uniform thickening on all walls.
Annular Collenchyma (rare)

9. Distribution in
Plant Body
Hypodermis of dicot stems –
sunflower, tomato, pumpkin.
Leaf midrib and petiole –
celery, spinach.
Rare in roots; absent in
monocots.

10. Functions of
Collenchyma
Mechanical Support – resists bending
forces.
Flexibility – allows organs to bend without
breaking (petioles, young stems).
Elasticity – tissue stretches and returns
to original position.
Photosynthesis – when chloroplasts are
present (chloroplast-rich collenchyma).
Protection – supports growing regions
without restricting growth.

11. Adaptive
Significance
Provides support during growth
(unlike sclerenchyma which is rigid).
Helps in withstanding wind and
mechanical stress.
Important in climbers and
herbaceous plants.