This name is a synonym of Phlox stansburyi (Torr.) A. Heller.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 25800762) with original publication details: Rep. U.S. Mex. Bound. 2(1): 145 1859.
This name was in version 1 of The Plant List, record tro-25800762.