In Iran, Polygonum s.l. (Polygonaceae) comprises 13 annual species with a complex taxonomic situation. There are great morphological similarities between some of the species. Under this project, leaf anatomical studies of 38 populations from different habitats are used to distinguish different taxa. A total of 15 qualitative and quantitative morphological characters are studied. Species and relationships between populations and diagnostic value of the anatomical features are considered. Calcium oxalate crystals are found in most studied taxa. Statistical analysis confirms the diagnostic value of leaf anatomical features.
