1797 Bidens cernua L.

This variable species occurs in most of Europe and disjunctly through Asia over to N. America. It is favoured by clearings near fens and brooks. It is considered indigenous in N. America (Fernald, Manual 1950, p. 1501), although the occurrences in Alaska are adventive (Hultén, Fl. Alaska Neighbor. Terr., p. 884) and probably so in many other places. It is registered among the amphi-atlantic plants by Hultén (Amphi-atl., p. 278 and map 260). However, it shows a tendency towards a circumpolar distribution.