This name is a synonym of Symphyotrichum × finkii (Rydb.) G.L.Nesom.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 9E6DEF70-3D37-4E1E-885A-C738FC4745C7).
This name record (from TICA) was not included in version 1 of The Plant List. It is possible the same name was included from a different data source, to check this you can search for Aster finkii in version 1 of The Plant List.