This name is a synonym of Phlox sibirica var. borealis (Wherry) B. Boivin.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50118460) with original publication details: Morris Arbor. Monogr. 3: 126 1955.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:689667-1.
This name was in version 1 of The Plant List, record tro-50118460.