This name is a synonym of Magnolia macrophylla var. ashei (Weath.) D.L.Johnson.
The record derives from WCSP
(data supplied on 2012-03-23)
which reports it as a synonym (record 117699) with original publication details: J. Arnold Arbor. 57: 268 1976.
Full publication details for this name can be found in IPNI: http://ipni.org/urn:lsid:ipni.org:names:149303-2.
This name was in version 1 of The Plant List, record kew-117699, and has not been changed.