This name is a synonym of Sparganium fluctuans (Engelm.) B.L.Rob..
The record derives from WCSP
(data supplied on 2012-03-26)
which reports it as a synonym (record 266160) with original publication details: Manual ed. 5: 481 1867.
This name was in version 1 of The Plant List, record kew-266160, and has not been changed.