XVI International Botanical Congess
The Paleogene Spitsbergen flora consists of three floristic assemblages of different ages: early Paleocene, early Eocene and probably late Eocene. The lowest Barenzburg flora and Greenland's Atanekerdluk flora have a great number of common species and genera. This permits both floras to be treated within a single Thulean phytogeographic province. Paleocene flora from Ellesmere Island and the Rarytkin Formation from Northeast Asia also have many common elements with Thulean province. On the whole, circumpolar arctic flora was rather homogeneous in Paleocene. In the Eocene with spreading of Atlantic ocean the connections between Spitsbergen and Greenland weakened and floristic similarity with the Beringian region decreased greatly. During the Eocene Spitsbergen floras were temperate and had few links with more thermophilic European floras.