This name is a synonym of Dieteria bigelovii var. mucronata (Greene) D.R.Morgan & R.L.Hartm..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record C4ADB1CF-7C44-4247-87CD-00714D52114F) with original publication details: J. Wash. Acad. Sci. 30 471 1940.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:23025-2.
This name was in version 1 of The Plant List, record gcc-240, and has not been changed.