Non-uniform, patchy stomatal closure of a plant is a strong determinant of plant growth under stressful situation

Additional image:: 

The stomatal response of cassia (Cassia streata L.) and dhaincha (Sesbania rostrata L.) to a coalmine overburden (OB) substrate was studied with a view to rehabilitate such areas. Plants raised in unmined soil were used as controls. The mine OB induced significant increase in stomatal index (SI) with diminished stomatal size and a stomatal closure in the test plants.