This name is a synonym of Stipagrostis zeyheri subsp. sericans (Hack.) De Winter.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 394468) with original publication details: Bull. Misc. Inform. Kew 1939: 613 1940.
This name was in version 1 of The Plant List, record kew-394468, and has not been changed.