Biomorphological features, phenological development and winter hardiness of East Asian species of the genus <i>Cotoneaster</i> Medik. when introduced in the Komi Republic

The paper deals with the biological features of the East Asian species of the genus Cotoneaster Medik. when introduced in the Komi Republic. The features of vegetation, the dynamics of shoot growth, as well as the specificity of growth processes in the North, the degree of winter hardiness of introduced species, flowering and fruiting of plants of three species of this genus have been studied. Long-term observations have established that the studied plants have a long seasonal rhythm of development, they are characterized by late terms of the end of the growing season. Some species in summer, due to their high ability to regenerate shoots, quickly restore the crown, which allows them to enter the flowering and fruiting phases annually under conditions of introduction. Of the seven species, three have entered the generation period, and only two differ in the regular fruit formation. Plants of C. allochrous, C. bullatus, C. roseus, and C. amoenus differ in the late start and late end of the growing season, which affect their winter hardiness. C. dammeri, C. horizontalis and C. ascendens are recommended as the most promising plants for growing in the northern region with an early start and late end of the growing season. The decorativeness of the studied dendrointroducents, which persists during the growing season, is noted.