This name is a synonym of Symphyotrichum × amethystinum (Nutt.) G.L.Nesom.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 1E73C207-015C-461B-AD9E-6B8F2B4D3286) with original publication details: 744 1884.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:180809-1.
This name was in version 1 of The Plant List, record gcc-79493.