This name is a synonym of Carex laxiculmis var. copulata (L.H.Bailey) Fernald.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 225693) with original publication details: Fl. Plains N. Amer. 181 1932.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:299265-1.
This name was in version 1 of The Plant List, record kew-225693, and has not been changed.