Swedish botanist born in Stora Tuna, Dalama. Mosén gained his doctorate at Uppsala in (c. 1870), during which period he also collected plants in Brazil and worked as curator at the Stockholm Museum of Natural History (1872-1873 and 1876-1883). Mosén's South American expedition began in 1873, when he travelled to the home of expatriate Swedish botanist A.F. Regnell (1807-1884) in Minas Gerais, Brazil. He collected in this area until 1874, when he set off to explore Santos. He returned to Minas Gerais before travelling back to Sweden in spring 1876, after which his collections were added to the Regnellian Herbarium in Stockholm, where he was employed. The genus Mosenia Lindm. Was named in his honour.