This name is a synonym of Carex williamsii Britton.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 225326) with original publication details: Naturaliste Canad. 94: 522 1967.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:45938-2.
This name was in version 1 of The Plant List, record kew-225326, and has not been changed.