20th-century Norwegian botanists

Rolf Yngvar Berg (2 December 1925 – 25 August 2018) was a Norwegian botanist.
He was born in Oslo. He took the dr.philos. degree 1962 on the work Studies in Liliaceae, tribe Parideae. He was a curator at the Botanical Museum of Oslo from 1956 to 1962, professor of botany at the University of California, Davis from 1962 to 1965 and at the University of Oslo from 1965 to 1994. He has been a corresponding fellow of the American Botanical Society from 2003, and a fellow of the Norwegian Academy of Science and Letters. He died at the age of 92.

Eilif Dahl (7 December 1916 – 17 March 1993) was a Norwegian botanist and politician for the Labour Party.
He was born in Kristiania. His interest in lichens started with an early friendship he developed with Professor Bernt Lynge. Thanks to Lynge, Dahl was able to take part in the 1936 Heimland botanical expedition to eastern Svalbard and Kong Karls Land, and then a Danish-Norwegian expedition to Greenland the next year. His collections from these excursions were used as part of his cand. real. thesis that he presented to the University of Oslo in 1942. According to Hildur Krog, his most important lichenological contribution was his 1950 work Studies in the Macrolichen Flora of SW Greenland, which was a revised version of his thesis.Dahl was appointed professor of botany at the Norwegian College of Agriculture from 1965. His research interests centered on Arctic plants and lichen, plant geography and ecology. He was also a politician for the Labour Party, where he was a board member from 1965 to 1977. During the German occupation of Norway he took part in resistance work, and was a member of the clandestine intelligence organization XU. After fleeing to neutral Sweden and later to the United Kingdom, he served with the Norwegian High Command in London.The lichen genus Eilifdahlia, and its type species, Eilifdahlia dahlii, are both named in his honour.