structure and function of leaf

1. Epidermis – Outer layer of tissues


2. Cuticle – Waxy protective outer layer of epidermis that prevents water loss on leaves, green stems, and fruits.  The amount of cutin or wax increases with light intensity.
3. Leaf hairs – part of the epidermis


4. Palisade layer – A tightly packed layer of parenchyma tissues filled with chloroplasts for photosynthesis.


5. Chloroplasts – Sub-cellular, photosynthetic structures in leaves and other green tissues.  Chloroplasts contain chlorophyll, a green plant pigment that captures the energy in light and begins the transformation of that energy into sugars.


6. Vascular bundle – Xylem and phloem tissues, commonly known as leaf veins.


7. Spongy mesophyll – Layer of parenchyma tissues loosely arranged to facilitate movement of oxygen, carbon dioxide, and water vapor.  It also may contain some chloroplasts. 


8. Stomata – Natural openings in leaves and herbaceous stems that allow for gas exchange (water vapor, carbon dioxide, and oxygen).


9. Guard cells – Specialized kidney-shaped cells that open and close the stomata.