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 29205748) with original publication details: Ann. Sci. Nat., Bot., sér. 5, 5: 232 1866.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:812014-1.
This name was in version 1 of The Plant List, record tro-29205748, and has not been changed.