This name is a synonym of Philadelphus lewisii var. angustifolius (Rydb.) S.Y. Hu.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50307814) with original publication details: N. Amer. Fl. 22(2): 166 1905.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:192757-2.
This name was in version 1 of The Plant List, record tro-50307814.