Teuvo ("Ted") Tapio Ahti (born 1934) is a Finnish botanist and lichenologist. He has had a long career at the University of Helsinki that started in 1963, and then following his retirement in 1997, at the Botanical Museum of the Finnish Museum of Natural History. Known as a specialist of the lichen family Cladoniaceae, Ahti has published more than 280 scientific publications. A Festschrift was dedicated to him in 1994, and in 2000 he was awarded the prestigious Acharius Medal for lifetime contributions to lichenology. Source: Wikipedia (en)