Finnish botanist and lichenologist (1934 - ).
Teuvo "Ted" Tapio Ahti (born 14 June 1934) is a Finnish botanist and lichenologist who has made considerable contributions to the taxonomy and biogeography of lichens. Known particularly for his work on the lichen family Cladoniaceae, he has had a long career at the University of Helsinki beginning in 1963, and following his retirement in 1997, has continued his research at the Botanical Museum of the Finnish Museum of Natural History. His research output spans more than seven decades, comprising over 450 scientific publications across lichenology, mycology, and botanical science. Ahti has con