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 309849) with original publication details: J. Bot. 2: 276 1864.
This name was in version 1 of The Plant List, record kew-309849.