The article provides brief geobotanical characteristics of plant communities of three populations of R. iliensis Chrshan. found in the floodplains of the Ili and Sharyn rivers, and also presents the morpho-anatomical structure of vegetative organs (stem and leaf) of the species under study. R. iliensis Chrshan. is undoubtedly a rare, endangered species of the flora of Kazakhstan. Its distribution area is shrinking from year to year as a result of anthropogenic pressure on the environment. Biometric indicators of vegetative organs in samples collected from populations 1 and 2 were approximately the same. The indicators of samples collected from population 3 differed substantially. This is a completely natural process, since there are substantial differences in the climatic conditions of the upper and lower parts of the basin where the Ili River flows: a sharp increase in temperature and a decrease in precipitation from high to low hypsometric levels of the basin. Moreover, there is a gradual aridization of the territory from east to west. Naturally, this entails a change in both soil and vegetation cover and leaves its mark on the morpho-anatomical structure of vegetative organs. With this in mind, the authors recommend continuous monitoring of the state of the populations at the three sites where R. iliensis Chrshan. was found.