This name is a synonym of Potamogeton friesii Rupr..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 292423) with original publication details: Student Fl. Brit. Isl. 374 1870.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:1063336-2.
This name was in version 1 of The Plant List, record kew-292423, and has not been changed.