This name is a synonym of Philadelphus gordonianus var. columbianus (Koehne) Rehder.
The record derives from Tropicos
(data supplied on 2012-04-18)
which reports it as a synonym (record 50307815) with original publication details: Gartenflora 1896: 542 1896.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:192766-2.
This name was in version 1 of The Plant List, record tro-50307815.