comparative wood anatomy of four shrubs from sarab region

to understand the compatibility of xylem with dry climates, wood anatomy similarities anddifferences of four shrubs were investigated in dry and cold region of sarab (azarbaijan sharghiprovince). these shrubs were: pteropyrum olivieri, rosa canina, tamarix gallica, and rhamnuspallasii, while the wood anatomy of pteropyrum sp. is reported for the first time, in this research.after preparing microscopic sections of mature xylem and staining them, wood anatomy of studiedspecies were reported and compared. the results showed that pteropyrum olivieri and rosa canina arethe most similar in terms of wood anatomy while rhamnus pallasii and tamarix gallica have the leastsimilarities with each other. those anatomical features which compensate the drought stress weredifferent in these shrubs according to local distribution of studied species; among them was theoccurrence and intensity of spiral thickenings in vessels, the presence of vascular / vasicentrictracheids, and the size and grouping of vessels. tamarix gallica which were grown only near the lakehad the least adaptation to drought in its stem while rhamnus pallasii which could distribute in theharshest conditions were equipped with the best adaptive traits.