127 Najas flexilis (Willd.) Rostk.

This Eurasiatic and N. American species occurs in fresh and brackish waters. The range is incompletely known, especially in Asia. The species belongs to the amphi-atlantic plants (Hultén, Amphi-atl., p. 212 and map 194). It is known as a fossil, mostly of postglacial age, from several localities. The European finds are mapped. Cf. also Meusel et al. 1965, map p. 27.