This name is a synonym of Aristida palustris (Chapm.) Vasey.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 395329) with original publication details: Fl. South. U.S. 555 1860.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:19384-2.
This name was in version 1 of The Plant List, record kew-395329, and has not been changed.