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 402550) with original publication details: Sargentia 4: 9 1943.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:40415-2.
This name was in version 1 of The Plant List, record kew-402550.