This name is a synonym of Helianthus pauciflorus subsp. subrhomboideus (Rydb.) O.Spring & E.E.Schill..
The record derives from TICA
(data supplied on 2012-02-11)
which reports it as a synonym (record 7EFB08D0-A0EB-423A-BCFF-1D63565EA26B) with original publication details: 864 1991.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:1120992-2.
This name was in version 1 of The Plant List, record gcc-15882, and has not been changed.