CYTOGEOGRAPHY an‎d PATTERNS OF DISTRIBUTION OF THE GENUS ACANTHOPHYLLUM (CARYOPHYLLACEAE)

On the basis of new floristic works, a distribution map of the genus Acanthophyllum is nearly identical to the distribution of Irano-Turanian Region. Three centers of diversity with high numbers of species are distinguished in the genus Acanthophyllum: the western and northern parts of Afghanistan (12 species belonging to 5 sections), southern parts of Turkmenistan (13 species belonging to 4 sections), and north-eastern parts of Iran (14 species belonging to 4 sections). According to the chromosome data, the maximum number of diploids, tetraploid and hexaploid species are found in S Turkmenistan, NE Iran, and W Afghanistan (centers of diversity). Furthermore, the areas far from the centers of diversity contain polyploid species, which are derived from diploid ancestors. The data obtained from the density and diversity of the species, endemics, sections, and chromosome counts seem to indicate that W Afghanistan, S Turkmenistan, and North-east Iran, are the centers of origin of the genus Acanthophyllum