the plants that are found in the unforested parts of the arctic subregion and the unforested subantarctic islands of Antarctica. The polar flora includes several hundred species of lichens and mosses and as many as 1,000 species of vascular plants. Typical are species of Gramineae, Cyperaceae, Juncaceae, Salicaceae, Caryophyllaceae, Ranunculaceae, Cruci-ferae, Saxifragaceae, Rosaceae, Ericaceae, Scrophulariaceae, and Compositae. Many species are endemic; however, there are virtually no endemic genera. The wealth of species increases as one moves south.
The polar flora is a young formation, which arose 1–1.5 million years ago and developed first on high arctic areas not subject to solid glaciation. The flora was later enriched by the migration of species of a more southern origin and by the development of local species. The polar floras of the southern hemisphere are confined to islands that are isolated from one another. They are poorer than arctic floras but more differentiated, and there are some restricted endemics. Some of the genera are encountered in the northern hemisphere, but there are few common species.
REFERENCEArkticheskaia flora SSSR, issues 1–6. Moscow-Leningrad, 1960–71.
A. I. TOLMACHEV