This name is a synonym of Philadelphus incanus var. mitsai (S.Y. Hu) S.M. Hwang.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50077596) with original publication details: J. Arnold Arbor. 36(4): 342–343 1955.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:792269-1.
This name was in version 1 of The Plant List, record tro-50077596, and has not been changed.