This name is a synonym of Calamagrostis inexpansa A.Gray.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 407988) with original publication details: Grass. U.S. 50 1883.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:398169-1.
This name was in version 1 of The Plant List, record kew-407988.