This name is a synonym of Sparganium emersum Rehmann.
The record derives from WCSP
(data supplied on 2012-03-26)
which reports it as a synonym (record 266033) with original publication details: Rhodora 68: 436 1966.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:241073-2.
This name was in version 1 of The Plant List, record kew-266033.