This name is a synonym of Sparganium angustifolium Michx..
The record derives from WCSP
(data supplied on 2012-03-26)
which reports it as a synonym (record 266046) with original publication details: Canad. J. Bot. 56: 193 1978.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:241077-2.
This name was in version 1 of The Plant List, record kew-266046.