112 Potamogeton polygonifolius Pourr.

This species is restricted to Europe (except E) and adjacent part of Africa. Further, there are same reports from easternmost N. America. Thus, the species belongs to the amphi-atlantic plants (Hultén, Amphi-atl., p. 168 and map 150). In addition, P. distinctus A. Benn. in E. Asia and other closely related Asiatic types are tentatively mapped.