This name is a synonym of Carex atrata subsp. aterrima (Hoppe) Hartm..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 224971) with original publication details: Allg. Bot. Z. Syst. 5: 195 1899.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:298840-1.
This name was in version 1 of The Plant List, record kew-224971.