Аннотация
The work was devoted to the study of the ontogenetic structure of cenopopulations of Tulipaostrowskiana Regel – a rare endemic species of the Northern Tien Shan, perennial plant from the Lili aceae family. Cenopopulations of T. ostrowskiana has been studied in the territory of the Ile-Alatau StateNational Natural Park the (Kaskelen Gorge, the Big Almaty Gorge and the Kotyrbulak Gorge) and its surroundings. The study of research on the ontogenetic structure of cenopopulations revealed the influenceof insolation regime of slopes on the age structure and morphometric parameters. An assessment ofthe cenopopulation’s age structure showed the least quantity of generative individuals in the Kaskelengorge, apparently related to the fact that many generative individuals were eaten by the cattle on theterritory of this cenopopulations. The smallest of three collected cenopopulations was cenopopulation ofT. ostrowskiana found in the Kotyrbulak gorge, where the anthropogenic factor – construction of countrycottages and collection of flowering plants – had the greatest influence. Here, the area of this species’growth is constantly decreasing. The average density of the cenopopulations at 20 test sites ranged from2.37 ± 0.28 to 3.82 ± 0.84 individuals per 1 m2. In order to find similarities and differences in the cenopopulations of T. ostrowskiana, morphological and anatomical studies were made. During the studying, the first cenopopulation demonstrated morphological polymorphism in the flower color and formof the leaf. We found differences in the anatomical structures: in the uppermost epidermis the outer cellwall was toothed in shape, in the lowermost one, there was no teeth. In virginal individuals, the lininglayer of the conducting beams was not fully developed, while in generative individuals it was completely formed. Conductive beams in the peduncle are collaterally closed and scattered throughout thepeduncle.Key words: endemic species, rare species, Tulipa ostrowskiana, cenopopulation, morphology, anatomy, ontogeny.