Eco-education Division & Botanic Garden, National Botanical Research Institute, Rana Pratap Marg, Lucknow- 226001, India
Foliar surface of plants is continuously exposed to the surrounding atmosphere and is, therefore, the main receptor of particulate pollutants. This physical trait can be used to determine the level of particulate pollution in the surroundings, as well as the ability of individual plant species to intercept and mitigate particulate pollutants. In the present study, leaf cuticle characters of four common roadside plant species, namely Bougainvillea â€˜Maharaâ€™, Terminalia arjuna (Roxb.) Wt. and Arn, Cassia fistula Linn, and Polyalthia longifolia Thw. were studied from sites with heavy particulate pollutants in the atmosphere and compared with those of control/ non polluted environs to evaluate their respective pollution mitigating ability. The particles deposited on the leaf surface were 2.5 to 10.0 Î¼m in size and the dust load was recorded in the trend of T. arjuna (2.31 mg/cm2)> C. fistula (1.47 mg/ cm2) > B. â€˜Maharaâ€™ (1.33 mg/cm2) and P. longifolia (0.97 mg/cm2). The increase in the size and frequency of epidermal cells and stomata were observed. Cuticle rupture was a major injury symptom, that was observed in T. arjuna, C. fistula and P. longifolia while no cuticular damage was not observed in B. â€˜Maharaâ€™. On the basis of these observations it can be concluded that B. â€˜Maharaâ€™ is a dust mitigator and it adsorbs and / or absorbs the pollutants from the environment in which it grows.