XVI International Botanical Congess

North Okhotsk seacoast native flora includes 865 species of 287 genera and 86 families, while complete list of 9 islands of this territory containes 384 species of 184 genera and 67 families. Only 10 families represent 60% of floristic diversity. According to floristic richness decreasing they are arranged as Poa-Cyp-Ast-Ran-Car-Sal-Ros-Br-Jun-Sax (first letters of the names) on the mainland. This family range reflects the general peculiarities of regional flora. But the same species form the different range of the richest families in the island flora: Po-Cyp-Ast-Ran-Ros-Jun-Eri-Car-Scr-Br. The considerable stability of Ericaceae, Rosaceae, Juncaceae, Scrophulariaceae in the island flora seems to be reflection of modern island conditions: mountainous relief, maritime climate and strong winds. These ecological factors have stronger effect on the islands, than on the mainland.