INTRODUCTION OF MOCK-ORANGE (PHILADELPHUS L.) IN THE HUMID SUBTROPICAL ZONE OF RUSSIA

Representatives of the genus mock-orange (Philadelphus L.) from the Hydrangea family are of great interest for use in landscaping parks and squares in our region. The objects of research were mock-orange cultivars and species growing in parks and squares of our region. The aim of the research was to study the morphological and biological characteristics of representatives of the genus Philadelphus in the humid subtropics of Russia. The paper considers the results of the long-term introduction and acclimatization of chubushnik on the territory of the Black Sea coast of the Caucasus. A comparison of morphological and biological features in 18 cultivars and species of representatives of the genus mock-orange was carried out. The characteristics of such signs as the height and shape of the crown, leaves, and the size of inflorescences, flowers and petals, the number of flowers in the inflorescence, the colour of the sepals and calyx, and the pubescence of the leaves’ lower surface are given. Cards describing the cultivars have been compiled. As a result of phenological observations, it was found that mock-orange flowering in humid subtropical conditions lasts from 20 to 50 days – from the early May to the mid July. The longest flowering was observed in the species of Philadelphus coronarius, Ph. inodorus var. grandiflorus, Ph. × zeyheri and cultivars Ph. ‘Glacier’, Ph. ‘Zhemchug’, Ph. ‘Romashka’. The shortest flowering period was observed in the species of Philadelphus pekinensis, Philadelphus pubescens var. intectus. It is also shown that the biodiversity of mock-orange species and cultivars on the Black Sea coast of the Caucasus is mainly limited by collection territories. It is necessary to include the native species Ph caucasicus into the selection, as well as it is more effective to carry out an introduction search for new highly decorative, resistant cultivars for use in the regional landscape gardening.