Gunnar Bror Fritiof Degelius (
né
A birth name is the name of a person given upon birth. The term may be applied to the surname, the given name, or the entire name. Where births are required to be officially registered, the entire name entered onto a birth certificate or birth reg ...
Nilsson until 1932; 27 January 1903 – 22 July 1993) was a Swedish
lichenologist. Between the publications of his first and final scientific papers, Degelius had a 70-year-long research career. While he was best known for his expertise on the lichen genus ''
Collema
''Collema'' (jelly lichen) is a genus of lichens in the family Collemataceae. The photobiont is the cyanobacterium genus ''Nostoc''.Dobson, F.S. (2000) Lichens, an illustrated guide to the British and Irish species. 4th edition. Richmond publish ...
'', he also wrote important papers on lichen biology and ecology,