In this study, which was conducted on the Tigris River in Salah al_Din Governorate at five stations (Al_Dhuluiya, Al_Alam, Al_uwainat, Balaj Tikrit, and Baiji) the differences were identified through morphological and anatomical comparisons of the following species: Typha domingensis, Eichhornia crassipes, Nasturtium officinale, using the electron microscope. The study included the anatomy of cross sections of the stem of the studied species .The results showed a difference in the internal structure of the stem, especially in the cortex area, as the cortex in Eichhornia crassipes contained a much larger aerial tissue than Typha domingensis, species, which contained a larger aerial tissue than the Water hyacinth species Nasturtium officinale .The morphological study included the shape of the stem, The stem of Typha domingensis plant is cylindrical and straight, reaching a length of about 1-3 meters, and most of its types are unbranched. As for the stem of Eichhornia crassipes plant, it is short, reaching a length of about 10 cm, while the stem of Nasturtium officinale plant is about 60 cm long.