This name is a synonym of Aristida cognata Trin. & Rupr..
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 25507324) with original publication details: Sp. Gram. Stipac. 128 1842.
This name was in version 1 of The Plant List, record tro-25507324, and has not been changed.