The paper presents the results of a comprehensive assessment of the viability and decorativeness of 20 samples of 17 taxa of the genus Crataegus L. when introduced into the Kola North. The study is one of the stages of a systematic description of the adaptive state of plants of the genus Crataegus when introduced into the conditions of the Far North. The main part of the studied samples are highly decorative quite viable plants that have high winter hardiness, maintain their growth shape, are able to produce germinating seeds, and have attractive inflorescences and fruits. C. chlorosarca, C. chlorosarca f. pyramidalica, C. cuneata, C. dahurica, C. douglasii, C. flabellata, C. laevigata, C. maximoviczii, C. pinnatifida, C. sanguinea, C. x schroederi. C. arnoldiana, C. canadensis and C. foetida are nonviable and undecorative plants. For the introduction of promising species of the genus Crataegus into the landscaping of cities of the Kola Peninsula, preliminary testing is required. Maintaining a highly decorative state is possible while observing the care of woody plants.

Polar-Alpine Botanical Garden-Institute (PABGI) is the northernmost in Russia (67о38'N.) and one of the few botanical gardens in the world inside the Arctic Circle. It has a unique collection of live plants, extensive herbarium funds. The article contains a list of the introduced woody plants in the PABSI collection fund. In 2018, the collection funds of woody plants included 27 families, 57 genera, 271 species, 21 subspecies, 14 species, 17 forms, 22 varieties and 22 hybrids. For the overwhelming majority of tree species introduced in PABGI, the presence of flowering / pollination and fruiting / seed production phases of different regularity is characteristic. The collection has 2 species included in the Russian Federation Red List. In the regional Red Lists of Russia there are 232 samples of 78 taxa of woody plants introduced in the PABGI. According to the list of rare species of IUCN, 298 samples of 106 taxa of woody plants have one particular international protection category or another.

The article contains а hst of introduced specimens of the genus Spiraea L. in the Polar-Alpine Botanical Garden-Institute located abovethe Arctic Circle. The collection fund ofthe Polar-Alpine Botanical Garden-Institute contains 51 Spiraea specimens belonging to 12 species, 1 subspecies, 3 varieties, 4 cultivars and 2 hybrids. Most of the introduced accessions аге of seed origin. The age of the collection spireas is from 4 to 79 years. The article gives а comprehensive assessment of the viability and decorativeness of introduced plants of the genus Spiraea in the Kola Subarctic. Evaluated the degree of hgnification of the annual shoot, winter hardiness, retention of gmwth fonn, shoot-fonning ability, height gain, abihty to generative development, methods of reproduction in culture, crown architectonics, duration and abundance of flowering, color and size of flowers and inflorescences, attractiveness of fmits, color range of autumn leaf color, leafing duration, plant агата, damage, correlation between viability, decorative effect and the period of being in the experiment. Observations for 2000-2020 were used in the work. А verage score of winter hardiness of introduced S. betuhfoha, S. chamaedryfolia, S. nipponica, S. media 1-3. S. japonica, S. japonica 'Norroboth', S. х bumalda, S. х bumalda 'Shraederii', S. х cinerea 'Grefsheim', S. х rosalba аге frozen to the snow cover and soil level. Winter-hardy species retain their vital fonn, weak-hardy ones are аЫе to restore their growth foпn Most of the studied samples Ыооm and bear fmit not annually, reproduction is possiЫe with artificial sowing, using cuttings. The studied samples can Ье divided into groups: quite viaЫe and viaЫe high and medium decorative; less and less viaЬle high and medium decorative; non-viaЫe and absolutely non-viaЫe medium and low decorative. The most viaЫe and decorative under conditions of introduction to the Kola Peninsula are S. betuhfolia, S. chamaedryfoha, S. nipponica, S. media. S. japonica, S. japonica 'Norroboth', S. х bumalda, S. х bumalda 'Shraederii', S. х cinerea 'Grefsheim', S. х rosalba have low decorative qualities due to low viability.

The paper deals with the introduction of genus Crataegus L. samples in Polar-Alpine Botanical Garden-Institute. The paper presents long-term periods of phenological phases onset of 14 Crataegus L. samples. Features of generative phenological development of 11 Crataegus L. samples are described. In the introduced Crataegus L. plants the time for the phenological phases passage depends on the origin and age. Adaptive advantages are plants of natural origin. This category of samples record phenophases of linear growth and lignifications of annual shoots which favorably affects the degree of adaptation. The phenophases onset of the majority of plants of the older and younger age groups is noted at close time. In plants of the older age group the phases of linear growth end and shoots lignifications are marked earlier than those of 18-19-year-olds. The indicators characterizing generative development (the duration of the prefloral period, flowering) are appropriate when assessing the adaptability of introduced plants. The majority of the samples are characterized by regular flowering and fruiting. The studied plants belong to the group with the average flowering onset. Short prefloral period contributes to early start and flowering end, earlier ripening of.

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