This name is a synonym of Helianthus niveus subsp. tephrodes (A.Gray) Heiser.
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 4D770ECF-E9AC-42A1-BFF5-A5A79C2E08D4) with original publication details: 90 1859.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:212290-1.
This name was in version 1 of The Plant List, record gcc-105468, and has not been changed.