Plant wilting due to lack of water. Photograph of a plant (^IOxalis succulenta^i) which has been deprived of water for five days. The leaves have wilted considerably. This is a normal reaction for plants deprived of water; the roots are unable to take up enough water to replace losses through the stomata on the leaves. The plant tries to reduce water loss by closing the stomata, a mechanism prompted by the release of abscisic acid from the chloroplasts. In mild water stress, this may save the plant until rain comes. Compare with healthy appearance of plant after watering (B740/186).