This name is a synonym of Symphyotrichum lateriflorum var. angustifolium (Wiegand) G.L.Nesom.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 801F384F-5F40-4EEE-BC99-7EE6B8F1928F) with original publication details: Rhodora 30 174 1928.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:23633-2.
This name was in version 1 of The Plant List, record gcc-56478, and has not been changed.