86 Alisma gramineum Lej,

This species occurs in Eurasia and N. America. The species s. str. is restricted to C. and E. Europe and parts of W. and C. Asia. The occurence in E. Canada may be adventive. The species may be regarded as an amphi-atlantic plant (Hultén, Amphi-atl., p. 278 and map 259). Within a restricted part of N. Europe, the closely related A. wahlenbergii (Holmb.) Juz. (syn.: A. gramineum subsp. wahlenbergii Holmb.) is distinguished. Cf. also Meusel et al. 1965, map p. 28.