Dicot monocot stem. with pictures

1. Dicot Monocot Stem
Helianthus annus & Zea mays
Sarfraz Ahmed
Govt. Post Graduate College Chishtian

2. Anatomy of Dicot Stem
Helianthus annus

3. Epidermis
• Outer Most layer
• Flattened cells
• Compact arrangement
• Cutinized
• Multicellular hairs
• Stomata presence
• Lack chloroplast

4. Cortex
• Two types
• 1- Hypodermis
• 2- General cortex

5. 1- Hypodermis.
• Outer layer
• Collenchyma cell
• Closely packed cell
• Spaces b/w cell is absent

6. 2- General cortex
• Cortical tissue
• Below hypodermis
• Parenchyma cell
• Intercellular spaces present

7. Endodermis
• Inner most General cortex
• composed barrel shaped tightly
packed cells
• Contain starch Grains
• Starch Sheath

8. Pericycle
• B/W Vascular bundle and Endodermis
• Sclerenchyma cells alternating
parenchyma cells
• Heterogeneous

9. Vascular Bundle
• Conjoint
• Collateral
• Open (Cambium present)
• Arrange in rings

10. Pith
• Center rounded
• Polygonal thin wall
• Conspicuous intercellular spaces
• Pith part

12. Anatomy of Monocot Stem
Zea mays

13. Epidermis
• Outer Most layer
• Single layer cells
• Compact arrangement
• Cutinized
• Hairs Absent
• Stomata presence

14. Hypodermis
• Below the epidermis
• 3 layers
• Sclerenchyma intrepid by parenchyma
in stomatal region.
•

15. Ground Tissues
• Extend below hypodermis to cortex
• No differentiate in Cortex, pith,
endodermis, pericycle
• Thin walled parenchyma cell
• Have Spaces

16. Vascular Bundle
• Conjoint
• Collateral
• Closed (Cambium Absent)
• Peripheral Bundles
– More in Numbers
– Smaller in size

17. Vascular Bundle
• Vascular bundle Toward center
• Less in Numbers and Large in size.
• Surrounded by sclerenchyma sheath
• More conspicuous

18. Xylem
• Y- shaped
• Arms occupy by pitted, bigger vessels
forming Meta-xylem
• Tail: occupy by smaller, annular, spiral
proto-xylem
• In b/w Meta-Xylem pitted Tracheids
Found

19. Phloem
• Above Xylem
• Sieve Tubes
• Companion Cell
• Phloem parenchyma absent
• Proto-xylem pushed out inner crushed
inner meta-Phloem

20. Pith
• Center rounded
• Polygonal thin wall
• Conspicuous intercellular spaces
• Pith part