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In the M.M. Gryshko National Botanical Garden National Academy of Sciences of Ukraine (Department of Cultural Flora), which is located in the north of the right bank of the forest-steppe zone, is being conducted for the introduction tests of plants of the species of the genus Isodon (Schrad. Ex Benth.) Spach. Representatives of this genus by number of species are most concentrated in East Asia – China, Korea and Japan, where they have long been known as medicinal plants and are used in traditional medicine, in particular, for the treatment of oncological diseases.In Ukraine, the Isodon genus is little known. During 2012–2018, the object of complex research was Isodon japonicus (N. Z. Burm) Hara var. glaucocalyx (Maxim.) H.W. Li. The article presents the results of studying the large life cycle of this plant species during the introduction. To establish age periods and plant conditions, classical methodical approaches are applied.The descriptive part of the work presents key morphological features that reflect changes in the shoot and root systems that a plant experiences during life. According to the duration of the study period, it was found that individuals of I. japonicus var. glaucocalyx undergo pregenerative and generative periods of development and all age states corresponding to them. It has been established that seedlings are characterized by the presence of two cotyledon leaves of a renal form, having a notch at the apex, and fragmentary lignification of root sections, which is a rather rare phenomenon. Juvenile plants lose cotyledon leaves, the shoot from the round becomes four-sided, the main root thickens. In immature plants, the shoot is stretched by lengthening the internodes, the leaves acquire the signs and dimensions of the present. In the virginal state, second-order shoots develop in plants, rhizome begins to form. For young generative individuals, there are 2–3 shoots, the development of a pair of skeletal roots, the beginning of the formation of caudex. This age condition begins for the vast majority of individuals in the first year of life. Adult generative plants reach a maximum in the development of the shoot and root systems: they have 3–5 vegetative-generative shoots, many-headed dense caudex. Spring renewal takes place: from the renewal buds – vegetative-generative shoots, dormant buds – vegetative shoots and from the buds of the plagiotropic rhizomes – partial single-shoot plants. This age condition lasts for three years. The age state of old generative individuals begins from the sixth year of plant life and is characterized by attenuation of organ-forming processes. This leads to a weakening of the escapes and root system and to the disruptive irreversible changes of the latter. [ABSTRACT FROM AUTHOR]

The studying of peculiarities of ontogenesis of three species of the genus Calycanthus L. in culture under conditions of Volyn Upland has allowed to reveal, that all species pass 3 periods. All species reach reproductive period for 4th year of life. The maximal decorative effect is observed for 5th year of life. It was found that rhythm of growth and development of the subject species match the natural climatic fluctuations of the new environment, and duration of vegetation period coincides with the period of stable positive air temperatures in Volyn Upland.