This name is a synonym of Magnolia cubensis subsp. cacuminicola (Bisse) G.Klotz.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 117483) with original publication details: Repert. Spec. Nov. Regni Veg. 85: 587 1974.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:554654-1.
This name was in version 1 of The Plant List, record kew-117483, and has not been changed.