This name is a synonym of Magnolia bintuluensis (A.Agostini) Noot..
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 117733) with original publication details: Gard. Bull. Singapore 31: 129 1978.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:554783-1.
This name was in version 1 of The Plant List, record kew-117733, and has not been changed.