Flower substances in the extremely disjunct species Oxytropis deflexa and their phytogeographical implications

• Published in: Canadian Journal of Botany
• Main Authors: Høiland, Klaus, Laane, Morten M.
• Format: Article in Journal/Newspaper
• Language: English
• Published: Canadian Science Publishing 1989
• Subjects: Plant Science; Norway; Finnmark; North Norway; Oxytropis deflexa
• Online Access: http://dx.doi.org/10.1139/b89-030; http://www.nrcresearchpress.com/doi/pdf/10.1139/b89-030

Oxytropis deflexa (Pall.) DC. is found on a global scale mainly in three extremely disjunct areas. This interesting pattern arose probably 10 000 years ago as a result of the termination of the Weichselian glaciation. In Europe the only known growing sites are in Finnmark, north Norway, where fewer than 500 specimens occur on two ecologically characteristic areas comprising only a few hectares. The species is known from localities in Asia 5000 km apart and also from North America. Plants from the main distribution areas differ in a number of characteristics. By examining the flower substances by thin-layer chromatography and by constructing dendrograms by the UGPMA procedure and using principal-coordinate analysis we found the Norwegian specimens to be chemotaxonomically isolated from American and Asian populations. The special floral chemistry found in the Norwegian population probably evolved during postglacial times. Because the Norwegian specimens seem thermophilous, it appears unlikely that the species survived the last glaciation on eventual coastal refuges in north Norway, as has been proposed by others. Our findings do not contradict a view that the plant migrated westward from ice-free areas in north Asia in early postglacial time. The Oxytropis deflexa group thus allows studies of evolutionary processes that have occurred within a time scale of approximately 10 000 years.