This name is a synonym of Artemisia ludoviciana subsp. redolens (A.Gray) D.D.Keck.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 575B71BD-A6C9-4A9B-A75A-DD0C01610261) with original publication details: 75 1923.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:20840-2.
This name was in version 1 of The Plant List, record gcc-68199.