This name is a synonym of Phlox diffusa subsp. scleranthifolia (Rydb.) Wherry.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 100363333) with original publication details: Mem. New York Bot. Gard. 1: 313–314 1900.
This name was in version 1 of The Plant List, record tro-100363333.