125 Najas tenuissima (A. Br.) Magn.

This species is restricted to E. Fennoscandia and W. Russia. Fossil finds (mostly of postglacial age) are mapped. The northern limit of N. minor All. is also mapped and so are fossil finds of this species. The knowledge of the distribution of these species is partly incomplete. Cf. world map in Meusel et al. 1965, p. 27.