This name is a synonym of Pseudolysimachion linariifolium subsp. dilatatum (Nakai & Kitag.) D.Y. Hong.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 29207828) with original publication details: J. Jap. Bot. 19(6): 162 1943.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:812152-1.
This name was in version 1 of The Plant List, record tro-29207828, and has not been changed.