The ecological plasticity observed in plants that inhabit different vegetation formations is often accompanied by morphological variations, the leaf being the vegetative organ with the greatest structural variation. In view of this concept, the leaf anatomy of five species of Polygala L. occurring in restinga (sandy coastal plain) and cerrado (savanna) areas in the state of São Paulo were analyzed in order to inventory their principal characters and describe their leaf structure, to thus compare them and assess the possibility of verifying structural patterns common to the ecological conditions of both vegetation formations. The species studied were: P. cyparissias A.St.-Hil. & Moq., P. laureola A.St.-Hil. & Moq., P. paniculata L. found in restinga, and P. angulata DC. and P. violacea Aubl. emend. Marques occurring in campo cerrado and cerradão margin areas, respectively. The middle region of the leaf blade and petiole proximal region of each leaf were processed following the usual techniques for scanning electron and light microscopy. The results show two structural patterns common to the species from the restinga and cerrado area formations: mesomorphic characteristics are observed in P. laureola, P. paniculata, and P. violacea, and xeromorphic in P. cyparissias and P. angulata.
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