HISTORY AND AGE OF SOME ARCTIC PLANT SPECIES 219 



From all 1 have said above, it can be concluded that the Arctic flora is in a 

 great part Preglacial and only a small portion of it can be dated to the Late 

 Pleistocene. It was formed during the Neogene and Pleistocene partly from 

 plant species occurring in the Arctic itself, partly from plants of American 

 and Eurasiatic mountain ridges. 



1 am indebted to Miss Jaroslava Riedlova for help with the statistical 

 problems, and to Dr. Lumir Klimes for correcting my English. The nomen- 

 clature followed in this paper may be found in Hadac (1942, 1960) and Love 

 and Love (1961b). 



REFERENCES 



Dahl, E. (1946). On different types of unglaciated areas during the Ice Ages and their 



significance to phytogeography. New. Phytol. 45, 225-242. 

 Dahl, E. (1958). Amfiatlantiske planter. Blyttia 16, 93-121. 

 Hadac, E. (1941). Et bidrag til historien om Bjornoyas flora. Natuien 1941 (5). 

 Hadac, E. (1944). Die Gefasspflanzen des "Sassengebietes" Vest-Spitzbergen. Noiges 



SvalhanI og Ishavsumlersokelser, Skrifter No. 87, 1-71. 

 Hadac, E. (1948). On the history of the flora of Iceland. Studio Botanica Czechoslovcika9, 



18-25. 

 Hadac, E. (1960). The history of the flora of Spitsbergen and Bear Island and the age of 



some Arctic plant species. Pieslia 32, 225-253. 

 Horn, G. and Orvin, A. K. (1928). Geology of Bear Island. Noiges Svalhaid og Islwvs- 



iindersokelser, Skrifter No. 15, 1-152. 

 Knaben, Gunvor (1959). Papa per-studier, med et forsvar for P. radicatiini Rottb. som en 



islandsk-skandinavisk art. Blyttia 16, 61-80. 

 Kjartansson, G. (1940). Uni aidur tertieru basaitspildnanna i nordanvcrdu Atlantshafi. 



Ndltiirufr. 10, 118-128. 

 Kupriyanova, L. a. and Tikhomirov, B. A. (1954). Issledovanie pyltzy is rastitei"nych 



ostatkov beresovskovo mamonta. DAN 45 (6). 

 LiNDQUiST, B. (1947). Two species of Betitia from the Icelandic Miocene. Svensk Bot. 



Tidskr. 41, 339-353. 

 Love, A. and Love, D. (1959). Biosystematics of the black crowberries of America. 



Canad. J. of Gen. et Cyt. 1, 34-38. 

 Love, A. and Love, D. (1961a) Some nomenclatural changes in the European Flora. 



I. Species and supraspecific categories. Bot. Notiser 114, 33-47. 

 Love, A. and Love. D. (1961b). Chromosome numbers of Central and Northwest European 



plant species. Opera Botanica 5, I-VIII, 1-581. 

 Love, D. (1960). The red-fruited crowberries in North America. Rhodora 62, 265-292. 

 Markov, K. K. (1951). Paleogeografiya. Moscow 1951. 

 RosHEVizH, R. Y. (1952). Analis arealov nekotorich kharakternich dlyaA rktiki slakov 



(eoarktikov). Areal I. 

 SoRENSEN, Th. (1945). Summary of the botanical investigations in N.E. Greenland. Medd. 



om Groenl. 136 (3), 1-179. 

 SoRENSEN, Th. (1953). A revision of the Greenland species of Piiccinellia Pari. Medd. om 



Groenl. 136(3), 1-179. 

 Strachov, N. M. (1948). Osnovy Istoricheskoy Geologii I-II. Moscow-Leningrad. 

 Srodon, a. (1954). Flory Plejstocenskie z Tarzymiecltow nad Wieprzem. Warsaw. 

 Tikhomirov, B. A. (1946). K filotzenogenesu nekotorich rastitelnych formatziy arkticheskoy 



Evrasii. Bot. Zlwrn. 31 (6), 27-41. 

 ToLMACHEV, A. I. (1952). K istorii rasvitiya flor sovetskoy Arktiki. Areal I. 

 Vassil'ev, V. N. (1961). Rod Empetnim. Akad. Nauk SSSR, Leningrad 1961. 



