Abstract: Taxonomical characters within the species Calligonum comosum L`Her have been studied grown in two different deserts in Saudi Arabia, Nefoud El-Shakika and El-Dahnaa. Vegetative morphological characters, especially plant length and width, showed great variations within the plant collected from the two different regions. Floral morphological characters are more stable, except the fruit color which was different in the two deserts. Anatomical characters as well as mineral contents varied in response to change in locations. The variations in these characters are discussed according to the difference in climates and water availability.