This name is a synonym of Najas marina var. intermedia (Wolfg. ex Gorski) Rendle.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 309126) with original publication details: Bull. Misc. Inform. Kew 7: 29 1952.
This name was in version 1 of The Plant List, record kew-309126.