Gunnar Seidenfaden (1908 – February 9, 2001) was a Danish diplomat and botanist. He was Danish ambassador in Thailand 1955-1959, and in the U.S.S.R. 1959-1961. He was an expert on Southeast Asia Orchidaceae. He published several multi-volume works on orchids, e.g. The Orchids of Thailand – A Preliminary List (with T. Smitinand) and Orchid Genera in Thailand vol. I- XIV. These works are strictly taxonomic and floristic, but decorated with Seidenfaden’s own drawings of flower parts as seen under the dissection microscope.
Gunnar Seidenfaden studied botany at the University of Copenhagen 1926-1934. He was soon involved in botanical investigation in Greenland. From 1928, he spend six summers in Greenland, partly as a manager of Lauge Koch’s Three-year Expedition to East Greenland. Unfortunately, he failed his master exam (“magisterkonferens”) in botany and turned to studies of economy and political science; graduating as “cand.polit.” in 1940. He was then employed by the Danish Ministry of Foreign Affairs. After his ambassador years, he headed the juridical office of the ministry until 1967. He continued to take assignments as Danish envoy at international conferences on environmental matters, e.g. CITES (1973), Helsinki Convention (1979), and the Bern Convention (1979).
In 1938, he won a Scandinavian contest for the best popular science book with “Modern Arctic Exploration”.[1] During his time in Thailand, he initiated a long-standing cooperation with the Royal Thai Forest Department, with which he arranged a number of collecting expeditions until the mid-1980s.
He described at least 120 new species. The Orchid genera Seidenfadenia Garay, Seidenfadeniella C.S.Kumar, Seidenfia Szlach., Gunnarella Senghas, Gunnarorchis Brieger have been named to his honour, as has Fadenia, a genus of extinct Permian sharks.