This name is a synonym of Schoenoplectus nipponicus (Makino) Soják.
The record derives from WCSP which reports it as a synonym and as an illegitimate name (record 264023) with original publication details: Trudy Imp. S.-Peterburgsk. Bot. Sada 20: 345 1901.
Full publication details for this name can be found in IPNI: urn:lsid:ipni.org:names:313477-1.