This study compares the effect of ecological factors on phenotype plasticity in the natural populations of Acinos graveolens in Iran. In total, twenty six quantitative and qualitative morphological traits were examined in the sixteen populations at two sections: inter- and intrapopulation. In the interpopulation section, averages amounts of morphological characteristics of populations were examined, while in the intrapopulation, morphological features of the seventy six plant samples of the populations were investigated. The obtained data showed that these characteristics differed between and within the populations and the analysis of variance test and one-sample test have shown significant differences of all quantitative characteristics. The biplot Principal Correspondence Analysis (PCA-biplot) of traits showed some populations had indicator morphological characteristic(s) which were useful in detecting of these populations. Significant correlations were found between some quantitative characteristics with ecological factors. The studied populations were separated from each other in the PCA and Principal Coordinate Analysis (PCO) plots and the Unweighted Paired Group using Average method (UPGMA) tree. The PCA plot of morphological features showed that some characteristics separated from others and the rest ones were together and had overlapping. The individuals of the studied populations were separated from others in the PCA and PCO plots and the UPGMA tree of the morphological characteristics. Individuals of some populations arranged separately and placed far from others, but this condition was reverse in the rest populations and most of individuals placed near each other. The obtained data confirmed high variations within some populations.
