ABSTRACT: The effects of fluoride air pollution, the most phytotoxic of the common air pollutants, on Medicago sativa L. (alfalfa, lucerne) were evaluated. Samples of Medicago sativa L. polluted by fluorides emitted from an aluminum production plant in Iran and control non-polluted plant samples were collected and analysed for fluoride ion (F) content using an F ion-selective electrode. Seventy-four qualitative and quantitative leaf characteristics (71 morphological, 2 anatomical, and 1 fluoride content) were studied with the data being encoded and analyzed using the Chisquared method. The results showed the polluted plants had an increased F concentration and morphological changes, including decreased organ sizes, compared with the controls. The accumulation of F in leaf tissues and the leaf morpho-anatomical changes were considered to be adaptive reactions to F pollution which made M. sativa more tolerant to fluoride pollution.
