Epilobium hirsutum in the Åland Islands, SW Finland

Epilobium hirsutum L. is an introduced species in Finland with the first reliable findings made in the late 19th century. The number of new findings accumulated slowly during the period 1900–1929. From the 1930’s onwards, the number of findings grew rapidly and E. hirsutum has been found in 153 grid squares of 10 km × 10 km size in the southern part of Finland until 2012. The first information of the species in the Åland Islands is a note in the literature from 1821 and the first collected specimen in the Åland Islands is from the municipality of Sund in 1873. However, both these are doubtful as they were not noticed in Finnish vascular plant floras later on. The first reliable finding is from 1973 and thereafter the localities with E. hirsutum increased with four more during the 1970’s, eight new during the 1980’s, fourteen new during the 1990’s and 35 new localities during the period 2000–2013. It thrives chiefly in man-made habitats in the cultural landscape and the most common habitats in the Åland Islands seem to be roadsides and road ditches. Although E. hirsutum has expanded during the last fifty years in Åland, it is not common yet and it has not been found in most of the eastern archipelago area. As an immigrant in our flora, E. hirsutum is now well established in the Åland Islands and it will probably be more common in the future. However, it seems that it is not a harmful invasive weed in Åland