Erodium (Geranaiceae) species are distributed in different habitats of Iran. Some species are of medicinal importance while some are well known weeds. In arid and semi-arid regions, E. cicutarium has had some importance as a forage plant and is an important grazing plant and source of protein supplements to straw for ruminants in semi deserts and wastelands of the Middle East. There is no information on its population genetic structure, genetic diversity, and morphological variability in Iran. Due to the medicinal importance of this species, a genetic variability and populations? structure study is performed studying 15 geographical populations of E. cicutarium Therefore, we used six inter-retrotransposon amplified polymorphism (IRAP) markers and 15 combined IRAP markers to reveal within and among population genetic diversity in this plant. AMOVA test produced significant genetic difference (PhiPT = 0.39, P = 0.010) among the studied populations and also revealed that, 55% of total genetic variability was due to within population diversity while, 45% was due to among population genetic differentiation. Mantel test showed positive significant correlation between genetic distance and geographical distance of the studied populations. Networking, STRUCTURE analyses and population assignment test revealed some degree of gene flow among these populations. PCoA plot of populations based on morphological characters was in agreement with MDS plot of molecular data. These results indicated that geographical populations of E. cicutarium are well differentiated both in genetic content as well as morphological characteristics. Consensus tree based on morphological and genetic data separated some of these populations from the others suggesting the existence of ecotypes within this species.