This name is a synonym of Muhlenbergia expansa (Poir.) Trin..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 437759) with original publication details: Ess. Agrostogr. 176 1812.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:418426-1.
This name was in version 1 of The Plant List, record kew-437759.