(i) If the water content of the leaves decreases due any reason, the guard cells turn flaccid, thereby closing the stomatal opening and transpiration stops.
(ii) Some plants have sunken stomata whereas others have reduced number of stomata to reduce transpiration.
(iii) In some plants, leaves may be dropped or may be absent or changed into spines as an adaptation to reduce transpiration.
(iv) The leaves may be covered by thick cuticle such as in Banyan tree, so as to reduce transpiration.
