Books by Torben Jürgensen

Micranthes foliolosa (R. Br.) Gornall sensu lato is exciting in ­Sisimiut area, West Greenland. The genotype of ­Micranthes ­foliolosa develops six phenotypes, all dependent on the substrate temperature. Thus, Micranthes foliolosa can be used as a climate indicator. It has been found that cold phenotypes without flowers very rarely occurs together with warm phenotypes with many flowers. Cold phenotypes reproduce them exclusively by bulbils (asexual reproduction) while warm phenotypes have both asexual and sexual reproduction with insect pollination. The insects do not search for nectar glands but only for the red tip of the anthers, which the insect rips off. The insects tend to seek out specimens with triple capsules for a fourteen-day period around August 1st. Around September 1st, the capsules open and throw seeds. ­Micranthes foliolosa growth indicate a possible control of the plant by red staining (anthocyanin pigmentation). In this study Micranthes redofskyi may prove to be a ­Beringian variant of Micranthes foliolosa s.l., as Micranthes ­foliolosa var. sisimiutii is an Atlantic variant of the species.

Micranthes foliolosa nov. var. sisimiutii is characterized among others by its size and development of 3 capsules, which all opened to throwing seeds in the surroundings. Only the half of the normal 2 capsules opened for spreading seeds. The new variety is found growing near Sisimiut (Greenland) and the plant develops five characteristic growth forms, which all gathered to one of the investigated localities, loc. 2 at the Scout Lake (Nalunnguarfik) at Sisimiut. Micranthes foliolosa nov. var. sisimiutii will only be identified correctly by knowledge to a total local population. In normal botanical collections a single specimen of Micranthes foliolosa nov. var. sisimiutii can contain characters which easily can be misinterpreted belonging to other varieties or subspecies of the species complex Micranthes foliolosa and Micranthes redofskyi or partial Micranthes ferruginea. Micranthes foliolosa nov. var. sisimiutii have more original characters and must be considered to be close to a parent species which may have survived and evolved in the open land just south of the glacial maximum 21.000 years ago in North America. Because of the unique great variation at only one locality (loc. 2, Nalunnguarfik) it is vital for the species Micranthes foliolosa (R. Brown) Gornall and especially Micranthes foliolosa nov. var. sisimiutii Wilken & Jürgensen, why the locality must be protected and preserved for the future.