Department of Biology, Faculty of Science, University of Guilan, Rasht, Iran
Central Herbarium of Tehran University, School of Biology, University College of Science Tehran, Iran
University and Jepson Herbaria, University of California, Berkeley, California 94720-2465, USA
Leaf anatomy of 27 species of Potentilla L. (Rosaceae), representing 9 sections and four related genera, especially Tylosperma Botsch., Schistophyllidium (Juz. ex Fed.) Ikonn., Drymocallis Fourr. ex Rydb., and Sibbaldia L. from Iran were studied using light microscopy. The most outstanding characters of blade and midrib were measured. The result revealed a number of taxonomically important characters e.g., trichome types, stomata positions, mesophyll types, crystals location and vascular bundle shape. Three types of stomata, two main types of mesophyll and two main types of vascular bundles were identified. Leaf anatomical evidence is of taxonomic value and reflect the ecological differences in the studied species.