This name is a synonym of Arbelaezaster ellsworthii (Cuatrec.) Cuatrec..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 484B5C53-A978-4D40-979D-BCB4B038232E) with original publication details: 25 1951.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:284885-2.
This name was in version 1 of The Plant List, record gcc-115660, and has not been changed.