Noticeable variation was observed in a number of morphological characters in the Glycyrrhiza specimens in various habitats in north of Iran. To study these variations, two taxa related to the Hyrcanian region from all four known taxa of this genus in Iran, including Glycyrrhiza echinata, and G. glabra var. glabra were studied by numerical taxonomy using morphological characters in three provinces, Golestan, Mazandaran, and Gilan. A total of 15 populations were studied in terms of 60 quantitative and qualitative characters of vegetative and reproductive organs, and the obtained data were analyzed by SPSS software after encoding. Based on the PCA analysis, 11 components created about 98% of diversity, indicating the separation of relatively numerous characters for these taxa. Among these traits, the best one was the length of the pedicle. In the WARD cluster analysis, the populations of each taxon are located in a separate cluster and their position in each cluster is also significantly aligned with the longitude, which can be attributed to the significant influence of climate conditions, including relative humidity from west to east on the variety of peculiarities in these taxa. Based on the results of this study, taxonomic treatment of the studied taxa in Flora Iranica confirmed.
