The purpose of this work was to investigate ontomorphogenesis of Asphodeline lutea (L.) Rchb. (a rare Mediterranean species of plants for Ukraine) in culture, to analyze the features and describe plants in а different age stages and the sequence of their passage by individuals outside of the natural area in M.M. Gryshko National Botanical Garden of the National Academy of Sciences of Ukraine (Kyiv). In the article detailed morphological descriptions of plants in different age stages are given. The plants were studied in culture. Observations were conducted during 5 year period (2014-2019). The growth and development of individuals in this article are considered as components of ontogenetic changes in plants within a large life cycle. Ontomorphogenesis was studied by conventional methods. For the description of the ontogenetic development degree of individuals, the terms "age-stage" and "age-period" are used. To describe the variation of the passage by individuals of ontogeny stages we divided stages into ontomorphs, which determined the degree of development-degradation of plants. Due to the fact that A. lutea is included in the Red Book of Ukraine (2009), after research of the the specimens they were planted in the soil for further growth. It has been established that A. lutea plants go through four periods of ontomorphogenesis and eight age stages in culture. Plants annually bloom, form seeds and seedlings. As a result of observations of individuals, it has been established that A. lutea plants are drought-resistant and winter-stable in Kyiv, and their annual cycle of development depends on seasonal climatic variations. Asphodeline lutea is a perennial herb with a short rhizome and monocarpic generative shoots, vegetatively mobile. The underground part is a rhizome with renewal buds and stocking roots. Vegetative recovery occurs from underground buds. Pregenerative period lasts 5 years or more. Seedlings and juvenile plаnts are formed during one period of vegetation. Due to the degree of development of juvenile and immature plants they are divided into ontomorphotypes. Such differentiation determines the possibility of multivariate development in individuals. We noted that the virginіle plants can be represented as a separate shoots or а clone, that is formed as a result of "tillering". In the generative period a further vegetative growth is characteristic for A. lutea, which is successfully used for artificial vegetative reproduction of these plants in culture. Formation of subsenile and senile plants is a result of prolonged cultivation in one place or in stressful conditions. In the postgenerative period of ontogenesis for the preservation of plants in a culture, it is necessary to "rejuvenate" them by separating and planting members of clonе to a new place. Due to the biological characteristics of the species, the examination of plants for the study of the ontogenetic structure of cenopopulations is best carried out during flowering, as later on, an overland part of the juvenile species may already be absent, which will affect the assessment of the age range of the population.