Transpiration is the loss of water due to evaporation that occurs through stomata in the leaves. It helps in transporting water and minerals, cools leaf surfaces by evaporative cooling and maintains the shape and structure of plants by keeping cells turgid.
The process involved in transpiration:
The process of transpiration occurs when water moves through plants from the roots to the leaves, then changes to vapour as it leaves the plant. Transpiration cools the plant and also provides it with nutrients, carbon dioxide and water.
There are three types of transpiration:
- Stomatal transpiration:
This is the most dominant form of transpiration being responsible for most of the water loss in plants. It accounts for 90-95% of the water transpired from leaves. As the name suggests, the process involves the participation of the stomata or stomates, microscopic pores in the epidermis of the leaves.
- Cuticular Transpiration:
This type of transpiration is responsible for the loss of water in plants via the cuticle. Water vapour directly diffuses through the cuticle on leaves and herbaceous stems and escapes to the atmosphere.
- Lenticular Transpiration:
This type of transpiration is the loss of water from plants as vapour through the lenticels. The lenticels are tiny openings that protrude from the barks in woody stems and twigs as well as in other plant organs.