This name is a synonym of Magnolia obovata Thunb..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym and as an illegitimate name (record 117599) with original publication details: Fl. Jap. 236 1784.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:554715-1.
This name was in version 1 of The Plant List, record kew-117599.