This name is a synonym of Sparganium erectum subsp. microcarpum (Neuman) Domin.
The record derives from WCSP
(data supplied on 2012-03-26)
which reports it as a synonym (record 266117) with original publication details: Preslia 70: 114 1998.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:1002653-1.
This name was in version 1 of The Plant List, record kew-266117.