New combination in the genus Caulinia Willd. (Hydrocharitaceae)
The new combination in the genus Caulinia Willd. is published: Caulinia canadensis (Michx.) Val. Tikhom. comb. nova. Distinctive features of this species from C. flexilis Willd. s. str. are specified. C. canadensis is suggested to replace C. flexilis s. str. completely in Eurasia.