| Theodor Magnus Fries | |
| Birth Date: | 28 October 1832[1] |
| Birth Place: | Femsjö, Sweden |
| Death Place: | Uppsala, Sweden |
| Nationality: | Swedish |
| Field: | Botany, Lichenology |
| Author Abbreviation Bot: | Th.Fr. |
Theodor "Thore" Magnus Fries (28 October 1832 – 29 March 1913), was a Swedish botanist, lichenologist, and Arctic explorer. He was the son of the mycologist Elias Fries.[2]
Following in his father's footsteps, Fries studied botany, obtaining his doctoral degree in 1857 at Uppsala. He is credited for introducing the term in a commentary about the lichen genus Stereocaulon in an 1858 publication.[3] He became a member of the Royal Swedish Academy of Sciences in 1865 and professor of botany and applied economics at Uppsala in 1877.[4] Fries edited several exsiccata series.[5] His most notable work was Lichenographia scandinavica (1871–1874). He also produced a two-volume biography of Carl Linnaeus (1903).
Fries was part of two Arctic expeditions led by Adolf Erik Nordenskiöld, in 1868 and 1871.[6] From 1893 to 1899, he was the vice-chancellor of Uppsala University.[7] His sons Thore Christian Elias Fries and Robert Elias Fries also became botanists.