This name is a synonym of Magnolia garrettii (Craib) V.S.Kumar.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 119647) with original publication details: Bull. Misc. Inform. Kew 1922: 166 1922.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:554899-1.
This name was in version 1 of The Plant List, record kew-119647, and has not been changed.