Lallemantia is a small genus with 5 species, which one of them is Lallemantia peltata. This aromatic plant grows in a limited area of the Iran and is known as medicinal herb in folk medicine. We have no information on the infraspecific variations on morphological, anatomical and molecular features of this species. Therefore, in the current study; we investigated these variations on six geographical populations of it. These plants were used for morphological, anatomical and molecular investigations. GenAlex, GenoDive and PAST softwares were used for statistical analyses. In morphological study, we used fifteen characteristics. PCA bi-plot revealed some characteristics had diagnostic value in separation of the populations. The studied populations were clustered into two groups. We examined fifteen qualitative and quantitative anatomical variables. PCA loading revealed that some anatomical variables had the highest positive correlation and were the most variable anatomical characters among the studied populations. Based on the anatomical traits, theses populations divided into two groups. Ten ISSR primers were used for examination of genetic variations among the populations. The STRUCTURE analyses of ISSR data revealed two groups in theses populations that they were divided into two groups in MDS plot. The results of morphological, anatomical and also ISSR studies were similar. Clustering and ordination of the studied populations separated some of these populations from the others and suggest the existence of two groups within this species.