This name is a synonym of Carex brunnescens subsp. sphaerostachya (Tuck.) Kalela.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 225192) with original publication details: Amer. J. Sci. Arts 48: 143 1845.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:298970-1.
This name was in version 1 of The Plant List, record kew-225192, and has not been changed.