Included here is the Caspian Sea, the largest enclosed inland body of water on the planet. It is bounded by Russia to the northwest, Kazakhstan to the northeast, Azerbaijan to the west, Iran to the south, and Turkmenistan to the southeast.

Caspian Sand Dune Vegetation

Dune vegetation in the southern Caspian is confined to a relatively narrow coastal belt that can be broadly divided into a dry sand dune zone close to the sea and a wet sand dune zone further inland.

Caspian Dry Sand Dune Zone

This zone is dominated by psammophytes with some 40 species spread across 36 genera and 18 families. Of these, 13 are more or less restricted to sandy dunes in the Caspian area.  These include Agriophyllum squarrosum, Amaranthus spinosus, Arguzia sibirica, Artemisia tscherviniana, Cakile maritima, Chenopodium ambrosioides, Corispermum orientale, Corynephorus articulatus, Digitaria sanguinalis ssp. pectiniformis, Maresia nana, the Caspian endemic or near endemic Convolvulus persicus and Melilotus polonicus, and the Hyrcanian endemic Daucus littoralis ssp. hyrcanicus.

Five others species, Brassica tournefortii, Cerastium pumilum, Cerastium semidecandrum, Corispermum caucasicum and Plantago psyllium, were found to have a preference for sand dunes over other habitats, while the rest, some 22 species, were found to be frequently present on sand dunes. These included  Arenaria leptoclados, Catapodium rigidum, Cyperus rotundus, Imperata cylindrica, Juncus acutus, Lolium rigidum, Lotus corniculatus, Medicago minima, Medicago polymorpha, Melia azedarach, Paliurus spina-christi, Parapholis incurva, Petrorhagia saxifraga, Phyla nodiflora, Plantago lanceolata, Punica granatum, Raphanus raphanistrum, Salsola kali, Senecio vernalis, Silene conica, Tribulus terrestris and Vulpia myuros.

Caspian Wet Sand Dune Zone

This more inland zone has a higher water table with more or less saline or brackish soils. In some coastal areas, such as Boujagh coastline, Gilan Province, this zone can be over 50 m wide with many microhabitats. The most important species are usually Juncus acutus and Juncus maritima and many other plants can be found growing under tall stands of these. However, in some areas, shrubby species may be codominant or dominant. The most important of these are Paliurus spina-christi, Punica granatum, Rhamnus pallasi, Rubus sanctus and the Turanian endemic Tamarix ramosissima.  Other important species include Amaranthus chlorostachys, Amaranthus cruentus, Anagalis arvensis, Artemisia annua, Bupleurum marschallianum, Cerastium glutinosum, Conyza canadensis, Conyzanthus squamatus, Cynodon dactylon, Datura stramonium, Equisetum ramosissimum, Euphorbia turcomanica, Froriepia subpinnata, Henrardia persica, Kickxia elatina, Physalis alkekengi, Phytolacca americana, Polycarpon tetraphyllum, Saccharum ravanae, Solanum nigrum, Stellaria media, Trifolium campestre, Verbena officinalis and the endemic or near endemic Gleditsia caspica. Most of these species are well adapted to wet or humid habitats. The few more typical sand dune species found here include Carex extensa, Cyperus michelianus, Eleocharis caduca, Isolepis cernua and Soliva pterosperma.

References

Naqinezhad, A. 2012. A Preliminary Survey of flora and vegetation of sand dune belt in the Southern Caspian Coasts, N. Iran. Research Journal of Biology, 2: 23-29.