This name is a synonym of Carex atratiformis Britton.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 224769) with original publication details: Bull. Natl. Mus. Canada 216: 17 1966.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:45810-2.
This name was in version 1 of The Plant List, record kew-224769.