1. TRANSPIRATION
Transpiration is the process through which plants loose water in form of water vapour mainly through the leaves.

2. Transpiration stream

3. stomata

4. Movement of water up the plant

5. Types of transpiration
1. stomatal transpiration
2. cuticular transpiration
3. lenticular transpiration

6. Factors affecting transpiration structural factors roots
Plants with extensive root system have a high rate of transpiration than those with few roots.
Extensive roots absorb more water hence more is available in the sub-stomatal spaces

7. Leaf size
Large leaves have a large surface area over which transpiration takes place hence high rate of transpiration

8. Leaf structure Cuticle
A thick cuticle reduces the rate of transpiration
The cuticle in most case is waxy-wax reflect away the sunlight hence lower temperatures in the leaf
Wax is also water proof hence reducing rate of transpiration

9. stomata
-Number of stomata-the fewer the number of stomata the lower the rate of transpiration
-Position of stomata-the sun shines directly on the upper surface of leaves hence increasing the rate of vapourization thus high water loss
Stomata on the lower surface are sheltered from the suns rays hence lower water loss
-Sunken stomata-when the stomata are sunken water vapour accumulates in the sub-stomatal air spaces thus its not exposed to moving air hence reducing the rate of transpiration

10. Leaf fall
During periods of drought, some plants such as broad-leafed deciduous trees shed their leaves to reduce the surface area for water loss.
In some species of grass the aerial shoot dries up to ground level.
(e) Hairy leaves
In some plant, leaves are covered with hairs or scales. These trap a layer of still moist air on the surface of the leaves thus reducing transpiration

11. prep
Read and make notes on the environmental factors affecting transpiration