This is a 1985 reprint of a book originally published in Russian in 1939.
The present volume, No. IX of the Flora of the USSR, covers the families Droseraceae, Crassulaceae, Saxifragaceae, Hamamelidaceae, and Platanaceae, as well as the subfamilies Spiraeoideae and Pomoideae of the Rosaceae. Other subfamilies of Rosaceae are dealt with in Vol. X, as they could not possibly be accommodated in the present book.
The present volume includes such plants of economic importance as currants and gooseberries, pears, apples, and related genera. The wide range of species of these genera growing wild in the USSR are of interest to breeders as material for remote hybridization, selection of wildlings; and direct introduction. This material could be of great value for orchards and soft-fruit plantations in the USSR.
Many rosaceous species described in this volume have yielded, or may yield in the future, a considerable number of trees and shrubs for horticultural use. Numerous species of the Saxifragaceae and Crassulaceae may likewise prove to be of interest as ornamental plants.
The study of the material treated in this volume has led to the identification of about 70 new species. In conformity with international rules, the descriptions pertaining to these species are also given in Latin. It should be noted that this volume brings the number of species up to about half the total number of higher plants of the USSR, which presumably does not exceed 14,000 species.