keywords: Celosia argentea, Corchorus olitorius, simulated acid rain, stomatal index
The impact of acid rain, resulting from the industrial emissions on plants, is of global concern. This study investigated the effect of Simulated Acid Rain (SAR) on some quantitative leaf morphological characters and stomatal traits of Celosia argentea and Corchorus olitorius which are both cultivated for their edible succulent leaves, using standard established procedures. Young seedlings of the two plant species were exposed to SAR condition of pH 2.0 while control plants were exposed to distilled water (pH 7.0) for a period of five weeks. A marginal increase in morphological characters namely plant height, leaf numbers, leaf area and petiole length was observed in SAR-treated C. olitorius when compared with the control plants. However, reverse is the case in C. argentea where all the characters were significantly reduced (p<0.05) except petiole length which gave a marginal increase in SAR-treated plants. Stomatal traits were reduced in the two species except on the adaxial surfaces of C. argentea leaves. Overall, the possible mechanism by which C. olitorius respond to SAR is through reduction in stomatal index and area of guard cells on the adaxial surfaces of the leaf, both of which consequently slow down the rate at which water and energy are lost through transpiration.