Introduction of the species of the genera Cotoneaster Medik. and × Sorbocotoneaster pozdnjakovii Pojark. from the Siberian flora to the Botanical Garden acad. A. V. Fomin of Taras Shevchenko National University of Kiev (message 3 – × Sorbocotoneaster pozd

УДК 582.734.3+58.006:58.084(477-25)

Abstract

A spontaneous intergeneric hybrid of Sorbus and Cotoneaster – Pozdnyakov’s sorbocotoneaster (× Sorbocotoneaster pozdnjakovii Pojark.) is an endemic of the South Yakutia. It is known from the river basin Aldan in the areafrom the city of Tommot to the mouth of the river Uchura and on the Aldan-Amga interfluve. It grows in the undergrowthof sparse pine and larch forests on stony-gravelly limestone slopes. It was first found by L. K. Pozdnyakov, a forester,an employee of the Institute of Forest of the Siberian Branch of the USSR Academy of Sciences, on September 9, 1950,when examining forests on permafrost in Yakutia: “in the area of the confluence of the Aya-Sullalah river into Aldan,105–110 km down the Aldan from Tommot” (from the letter of L. K. Pozdnyakov to A. T. Grevtsova, 1982). The article provides data on the origin of the specimens × Sorbocotoneasters, the morphological description of leaves, flowers, fruits,the peculiarities of growth and development in conditions of Kiev, micrographs of pollen grains, micrographs of theendocarp of fruits of three forms, the beginning of the destruction of the scutellum and hypostyle from the ventral side ina hybrid of the third form. Botanical Garden named after acad. A. V. Fomin of the Taras Shevchenko National Universityof Kiev is the only ex situ conservation site in Eastern Europe of the unique Yakut hybrid × Sorbocotoneaster pozdnjakoviiwith leaves of the 1st, 2nd and 3rd forms.