109 Potamogeton obtusifolius Mert. & Koch

The distribution of this widespread Eurasiatic and N. American species is somewhat uncertain because of confusion with other species. This species belongs to the amphi-atlantic plants (Hultén, Amphi-atl., p. 62 and map 44), although with a circumpolar tendency. It is reported from Australia. Cf. also Meusel et al. 1965, map p. 25.