Taxonomic significance of inflorescence and seed characteristics in the genus Amaranthus in Iran

The genus Amaranthus (Amaranthaceae), with 14 native or cultivated species (total 17 species and subspecies), is distributed in different regions of Iran. Of these, 10 are known as weedy taxa. In the present study, we selected and analyzed the morphological and micromorphological characteristics of the inflorescence and seeds in Iranian Amaranthus taxa to investigate the diversity and to clarify the relationships among them. Scanning electron microscope (SEM) micrographs of seeds of 16 taxa were presented. In order to determine the similarity of the studied taxa and their classification in relation to the measured characteristics, cluster analysis was used by Ward method. The evaluation of data by Ward clustering and PCA biplot classification methods showed similar results. The results divided the taxa into three main groups, which do not fully correspond to the sections mentioned in the classification of this genus; however, confirm somewhat the close relationships of the taxa.